Family physicians often rely solely upon patients' recollections of events in the assessment and treatment of psychological complaints. One important method that is likely to enhance the quality and quantity of relevant clinical data is patient self-monitoring. Self-monitoring involves utilizing patients as self-observers and systematic recorders of information concerning their target complaint(s). Self-monitoring affords several advantages to both the patient and physician. It is especially useful as a basis for performing a functional analysis of behavior. The most valuable aspect of patient self-monitoring lies in the systematic collection and summarization of clinical information that is crucial for the assessment and treatment of psychosocial complaints.