This study set out to assess the effects on diagnosis and management of providing general practitioners with feedback of patients' scores on a depression screening instrument. One hundred and sixteen general practice attenders aged 16-64 with undetected depression were identified using the Beck Depression Inventory (BDI). The BDI scores of a random 45% were disclosed to the general practitioners. Subjects and medical casenotes were reviewed over 12 months. Thirty-one (27%) of subjects were later diagnosed as depressed. Rates of diagnosis were higher in the disclosed group, but only after six months. Rates of intention to treat were low, but were marginally higher for the disclosed group; they were much higher for patients diagnosed by the doctors themselves. Feedback of screening questionnaire results appears to be of limited value in enhancing general practitioners' detection or management of depression.