Behavioral, psychological, physiological and practical issues in the treatment of obesity are presented. These issues are discussed in terms of the responsibilities of weight reduction therapists, obese clients and behavioral treatment programs. It is argued that weight reduction therapists need to acquire knowledge about the psychological, physiological and dietary aspects of weight reduction in addition to adequate knowledge and training in the principles of behavior modification and psychotherapy. At the same time, obese clients are responsible for participating in and adhering to behavioral procedures. Finally, weight reduction treatment programs are responsible for completing clinical research, program evaluations, and long-term follow-up studies as well as for providing obese clients with opportunities for periodic consultation and continuous care. If these basic issues and responsibilities are adequately handled, the efficiency and effectiveness of the behavioral treatment of obesity may be improved. © 1979.