This case study describes the brief but intensive treatment of a young woman who complained of feeling depressed and had numerous somatic complaints. Interactional data based upon home observations and ratings played a prominent part in the treatment. Observing the patient’s behavior in her home was useful in that it 1. very quickly and powerfully focused the case as an interactional problem; 2. provided the therapists with specific behavioral information to be used in the treatment process; and 3. represented a methodology for evaluating behavior change. © 1969 S. Karger AG, Basel.