Objectives:
The aim of the article is to identify the development of the concept of social diagnosis that took place and takes place in social pedagogy. In this discipline, from the very beginning of its existence, the concepts of environmental diagnosis were developed as an activity preceding the necessary social action changing - improving the social world.

Material and methods:
The area of research are the concepts of social diagnosis developed in social pedagogy by the main creators of this discipline - from the beginnings of its existence up to modern times.

Results:
The analysis of reconstructed concepts shows that the social diagnosis undertaken in social pedagogy applies to both individuals and social groups - it identifies the environmental conditions of their life and functioning. Most often it concerns such areas as social conditions, participation in culture but also educational conditions and possibilities.

Conclusions:
It would be necessary to deepen the social diagnosis - also in the sphere of psychological experiences of the participants of social life and the level of their life - also showing new educational environments and their determinants.