This handbook outlines procedures for planning and conducting follow-up studies of clients involved in chemical dependency programs. It is organized into eight chapters. Chapter I discusses purposes and applications of client follow-up studies. Studies may be used in program evaluation, program design, and staff development. Also, the study itself can provide an extension of program services. Chapter II describes the content of the study. Topics include outlining the areas to be explored, organizing the areas into their fundamental components, and developing a questioning strategy that reliably probes each area. Chapter III focuses on sampling procedures, confidentiality, and additional sources of data to supplement the self-report of clients. Chapter IV considers procedural and cost arrangements with reference to comprehensiveness of the study, personnel requirements, confidentiality, financial resources, and consultation. Chapter V describes operating procedures such as compiling records for administering the study, locating and informing clients of the study, and pretesting study procedures. Chapter VI covers phases of data collection: planning for interviewer recruitment, selecting and training interviewers, and supervising data collection. Chapter VII discusses both computerized and non-computerized methods of arranging data for analysis. The final chapter outlines procedures for writing an evaluation report. (KC)