Peat swamp forest (PSF) is an ecosystem of global significance. It sequesters and stores atmospheric carbon, regulate hydrological system, provide habitat for many endemic wildlife, and deliver livelihoods support to thousands of local people. Despite these values, during the last several decades PSF have been subject to extensive deforestation and degradation globally. A significant portion (7%) of the Malaysia’s total land mass is PSF that are traditionally managed with the state governance system. However, depletion of this PSF has been continued due to various anthropological causes including intensive logging, drainage, fire, conversion to agriculture, oil pam, settlement, industry etc. Continued depletion of PSF with the centralized governance system (in other ways, here, state forest management, SFM system), and the success of community-based forest management (CBFM) approach in many countries of the world motivated several South-East Asian (SEA) countries to impart changes in their governance system from traditional centralized/state governance approach to CBFM approach. Recently, in Malaysia, specifically State Government of Selangor introduced CBFM approach in the governance of depleted PSF at Raja Musa Forest Reserve (RMFR) in collaboration with Global Environment Centre (GEC, a national non-government organisation). However, the success and/or failure of the newly applied CBFM approach in terms of PSF restoration and community development has not been fully explored yet. The aim of this research was to understand the effectiveness of community participation toward restoration and sustainable conservation of degraded PSF of RMFR in Peninsular Malaysia, with the following objectives: (i) ascertain characteristics of peat, peatland and peat swamp forest, and activities involve in PSF restoration through literature review, (ii) examine the formation and functions of social capital, and the level of community participation in PSF restoration, (iii) analyse the impacts of institutional setting and governance on sustainable conservation and community-based PSF restoration, (iv) assess ecological outcomes of community-based PSF restoration programme, and (v) examine the effect of management regimes of the PSF on local peoples’ socio-economic and environmental benefits. To attain these objectives, the study deployed a pluralistic research approach of social research and ecological (e. g. vegetation survey) study. For social research, both qualitative and quantitative data were collected through a stakeholders’ workshop (with the presence of 49 participants from federal and state Forestry Department, other government agencies, NGOs, local government, academics, local community leaders), four focus group discussions, five key informant interviews and 200 household interviews in four adjacent villages of RMFR. In addition, secondary data was collected from official documents of GEC local office. Building on the concepts and theoretical framework of social capital and level of participation, this research found that some social capital has been developed through forming three local organizations viz. Friends of North Selangor Peat Swamp Forest (FNSPSF), Junior Peatland Forest Ranger (JPFR) and Peatland Forest Ranger (PFR), and integrating another existing organization (Homestay agro-tourism Sungai Sireh) in the restoration programme. In addition, some structural social capital (bonding, bridging and linking) among local community, other similar organizations, NGOs and SSFD have also been developed. But trust (cognitive social capital) among local community, and GEC and SSFD was in question and economic development activities were also very minimal, which demotivated local community and thus showed low level of their participation in the restoration programme. I concluded to reform the organizational structure of local community-based organizations (CBO) by forming two site specific CBOs on local environment namely Forest Conservation and Recreation Village (FCRV), and Forest Restoration Village (FRV), in addition to the current FNSPSF for improving local involvement in the PSF restoration and community development programme. Based on Institutional Analysis and Development framework and concepts of forest property rights (specifically de facto rights), empirical qualitative and quantitative research was carried out on the effectiveness of the local community participation on PSF governance at RMFR; and the impacts of CBFM approach on the de facto rights. I found that CBFM regime had a significant impact on the reduction of exercising de facto rights, which might be related to improved monitoring and enforcement. Further, I identified seven major categories of actors who are actively involved in the PSF restoration programme; however, two actors such as GEC and SSFD play the key role in all governance functions and interact with most of the actors. FNSPSF (key local CBO), have very insignificant role and limited interaction with other actors in the current governance structure. The actors’ participation was enabled by a number of regional, national and local level strategy, policy, and agreements. Although the emergence of the current CBFM showed its effectiveness in the PSF restoration programme; however, limited participation of local community (in particular FNSPSF) in PSF governance posed the major threat to the sustainability of this multi-stakeholder PSF restoration programme. I recommended to put FNSPSF at the centre of the collaborative organizational structure with policy, capacity building and funding support to improve the efficacy and to sustain this newly emergent multi-stakeholder PSF governance. The study on the ecological outcomes of the community-based restoration programme was assessed by collecting data through focus group discussions and key informant interviews (for data on restoration approach), official documents (for data on plantation establishment, water table monitoring and fire incidences) and vegetation survey (for data on planted tree growth and natural regeneration data). Results revealed that PSF rewetting (e.g. improvement of water table) can be achieved with canal blocking and clay dyke construction; further, fire incidences can be reduced through improving water table, providing training on fire drill, creating awareness, and involving local community in forest vigilance. However, annual rate of plantation (about 30 hectares (ha) per year) was found low compared to the total targeted plantation area (1,000 ha). The composition of planted species is limited to only Euodia redlevi with some few other species e.g. Shorea leprosula, Myristica lowiana and M. pruinosa. The average survival rate is 65% with a MAI (mean annual increment) of diameter and height of E. redlevi decreased from younger plantations (3-year) toward older (5-, 7-year). Sixteen regenerating species was identified with an average of 17,798 seedlings ha-1. Natural regeneration was dominated by E. redlevi and only 10.6% of the regeneration could survived to the young tree stage. I recommend to expedite the plantation with diverse potential native species and giving emphasis on post-plantation maintenance. The perceived environmental and socio-economic benefits derived from the community-based restoration programme and local community’s willingness to participate revealed through four focus group discussions, five key-informant interviews and 200 household interviews. I found that CBFM approach has helped to improve some societal and economic benefits including introduction of nature-based recreation, increased income from eco-tourism and community nursery establishment, and nature education and research, and declined PSF conversion to other land uses. On the other hand, perceived environmental benefits including water storage and supply for irrigation, biodiversity and habitat conservation, carbon sequestration capacity of the community-based PSF restoration programme and the material benefits from timber and non-timber forest products (NTFP) supply has not showed any significant improvement yet. This study provides a number of recommendations which highlights institutional such as local level CBOs and multi-stakeholder governance structure, and legal reform, and capacity building of the local community through training and fund streaming to strengthen the community-based PSF governance in Malaysia. In addition, recommendations regarding ecological restoration points out to continue the canal blocking activities with proper maintenance and community patrolling, expedite the annual tree planting rate, increase the number of planted species, and enrichment plantation with diverse species in the planted and assisted natural regeneration forests. I highlight the potential of this study to influence policy space in Malaysia and other SEA countries, as they have similar socio-economic conditions, PSF degradation contexts, and community-based restoration possibilities.