The clinical significance of research findings is an important issue that, until recently, was often neglected. Statistical methods are available, however, to evaluate the meaningfulness of pre- to post-treatment change. The clinical significance of the National Institute of Mental Health Treatment of Depression Collaborative Research Program Data was evaluated. A substantial number of clients receiving treatment for depression made reliable improvements and had posttreatment scores that fell within a functional distribution. A small number of clients reliably deteriorated despite undergoing 12 sessions of treatment. No differences in clinical significance rates among treatment groups existed for measures of depressive symptoms. Treatments differed in terms of clinical significance on a measure of general symptom severity. There was substantial agreement among diverse methods of measurement regarding the identification of individuals making clinically significant change.