It is not well-known whether self-report measures and clinician-rated instruments for depression result in comparable outcomes in research on psychotherapy. We conducted a meta-analysis in which randomized controlled trials were included examining the effects of psychotherapy for adult depression. Only studies were included in which both a self-report and a clinician-rated instrument were used. We calculated the effect size (Hedges' . g) based on the self-report measures, the effect size based on the clinician-rated instruments, and the difference between these two effect sizes (Δg). A total of 48 studies including a total of 2462 participants was included in the meta-analysis. The differential effect size was Δ g=. 0.20 (95% CI: 0.10-0.30), indicating that clinician-rated instruments resulted in a significantly higher effect size than self-report instruments from the same studies. When we limited the effect size analysis to those studies comparing the HRSD with the BDI, the differential effect was somewhat smaller, but still statistically significant (Δ g=. 0.15; 95% CI: 0.03-0.27). This meta-analysis has made it clear that clinician-rated and self-report measures of improvement following psychotherapy for depression are not equivalent. Different symptoms may be more suitable for self-report or ratings by clinicians and in clinical trials it is probably best to include both. © 2010 Elsevier Ltd.