The three main questions dealt with in this article are: 'why have community participation in planning?' 'what is community participation?' and 'how can community participation be practised?' Planning in this context should be understood in a strategic sense as social policy development and implementation at a regional level. In answer to the first question, two common approaches to social planning and their shortcomings are briefly discussed, with reference to a taxonomy from Alan Walker's book Social Planning, A Strategy for Socialist Welfare. Community participation in social planning is a key characteristic of an alternative approach which addresses or avoids altogether the fundamental shortcomings of the other two. Issues of the practice of community participation in regional planning are examined through a description and analysis of the planning process undertaken by the Western Metropolitan Region of the Health Department Victoria. Some general conclusions regarding current trends in policy formation and public sector administration are also drawn.