High-value horticultural crops, including fruits, vegetables, flowers, aromatic plants and herbs, are key components of agricultural development and economic progress in developing countries. Tropical and subtropical fruit trees are normally grown in these areas, especially when they have a competitive advantage of being harvested when appropriate market windows occur. Intensive production systems, often involving intercropping of fruit trees and vegetables along with a staple grain crop such as maize, provide local population with a balanced, diverse, nutrient-rich diet, an increased income, improved health and well-being through reduction in poverty and malnutrition. This review focuses on three case studies in three continents, each of which has achieved remarkable success in a relatively short time: East Cape, South Africa; Chiapas State, Mexico; and the São Francisco River Valley, Northeast Brazil. Significant economic benefits accrued to smallholders, as well as locally and nationally in both Brazil and Mexico, while in South Africa final economic assessments have not been made, although smallholder farmers are receiving incomes that have not existed previously. Key elements in success of these projects included substantial initial funding from a Government or international source that enabled infrastructural development such as creation of irrigation systems in Brazil, selection and supply of quality planting material (propagated trees, plants, vegetable and flower seeds), provision of R&D expertise as well as extension specialists providing education and training. In addition, involvement of local farmers and communities, development of local farmer associations and 'champions' to provide leadership, addition of people with expertise in social, economic, technological, welfare and heritage knowledge is important for ongoing village progress and development. Major challenges exist in creation of a functional and efficient supply chain for postharvest handling, storage and transport, as well as creating stable and profitable market linkages for high-value horticultural products. The common elements in these projects have the potential to be transposed to other developing countries where they have the potential to serve as models for economic and social development.