This guidebook is both a practical tool and a source book to aid health planners assess the importance, extent, and impact of indigenous and private sector medical systems in developing nations. Guidelines are provided for assessment in terms of: use patterns; the meaning and importance to users of various available health services; and ways of combining or integrating indigenous, private, and public health services. The book is presented in four parts. Part I justifies looking beyond public health services to private and indigenous services in a health sector assessment. Part II summarizes current knowledge re: health belief systems around the world, Western-oriented private practitioners, and indigenous practitioners in order to give a sense of the range of beliefs and practices a user of the manual might encounter and how such beliefs and practices may influence program impact. Part III explores the question of social change and the controversy surrounding the integration of various health sectors in a single health program. Part IV describes several methodologies (requiring limited personnel and financial commitments) for assessing non-public health sectors. The guidebook is part of a series intended to assist health sector advisors, administrators, and planners in countries where the Agency for International Development supports health related activities. (Author/SB)