BACKGROUND We developed a comprehensive, 20-hour training programme for primary-care physicians, that sought to improve their ability to detect, diagnose and manage depression. We evaluated the effects of physician training on patient outcomes, using a pre-post design. METHODS In the pre-training phase of the study, we sampled 1834 consecutive patients of 17 primary-care physicians and evaluated 518 of these patients for the presence of depression. We measured outcomes of all patients with depression at 3 months and 1 year. The outcome measures were: severity of psychopathology; duration of depressive episode; and level of daily functioning. After the 17 physicians completed the training, we drew a new sample from their practices (498 of 1785 consecutive patients were evaluated for depression) and measured outcomes for the depressed patients. RESULTS We found an effect of the training on short-term outcome, particularly for patients with a recent-onset depression. At 3-month follow-up depressed patients whose physicians had received training had less severe psychopathology and patients with recent-onset depression also showed higher levels of daily functioning than patients of the same physicians prior to the training. The patients with a recent-onset depression that was recognized by trained physicians had shorter depressive episodes, but this was not statistically significant. At 1-year follow-up, all training effects had faded away. CONCLUSIONS Training primary-care physicians to recognize, diagnose and manage depression can improve short-term patient outcomes, especially for patients with a recent onset of depression. Patients suffering from a recurrent or chronic depression may need more specific interventions, both for acute treatment and long-term management.