The harmony restoration theory of health (HRT) is an existential phenomenological theory of health and ill health from an African perspective. The theory emanated from years of clinical practice of Peter Ebigbo in the mid 90s has its basic tenet, "he who is at peace with his world does not fall sick" and this is the root from which all other tenets of the harmony restoration theory stems. The harmony restoration theory of health was borne out of the African concept of illness. In Africa, the mind, the body and the society interact to produce health and ill-health. From clinical practice, it was observed that the African personality has three components, namely: the endocosmos, which is the relationship between the individual and himself; the mesocosmos, the relationship between the individual and the significant others in his environment; and the exocosmos, the relationship between the individual and his God or gods. This paper examines the HRT, traces its origin from the African traditional and contemporary religion, the socio-cultural, personological aspect of its derivation, its development and how it is applied in the treatment of psychological disturbances as well as in maintaining positive health. It also examines two case studies where the harmony restoration therapy was used and lastly, makes a case for its further exploration by other health care practitioners.