The strategy of diagnostic supervision, and the diagnostic conference, are outlined in this paper. Diagnostic supervision involves the supervisor and teachers in a process of recognizing needs, stating problems, and agreeing on objectives for the teachers' instructional improvement. The diagnostic conference, one tool used within the process, helps the supervisor diagnose the needs, interests, and abilities of teachers in relation to the needs of the school district. The Diagnostic Conference Planning Questionnaire (DCPQ) is a planning instrument using two lists--one concerning the role expectations for teachers, the other concerning job-related psychological needs of teachers. The teachers select the items of interest to them; the supervisor then meets with each teacher to discuss these selections. In the diagnostic conference the teacher is invited to share leadership so that it is jointly conducted. During the conference the needs of the teacher are identified, confirmed, and restated as problems to be solved. Objectives are agreed upon for problem solution and the strategies for reaching the objectives are selected and designed. This process is an ongoing dialogue between supervisor and teacher that is maintained for more than one conference period. The paper includes five recommendations for managing the process, a copy of the DCPQ, and a short reference list. (MD)