This paper draws attention to an important adverse outcome in depression, the occurrence of residual symptoms after partial remission. Among patients with definite major depression followed every 3 months to remission and thereafter, residual symptoms reaching 8 or more on the Hamilton Depression Scale 17-item total were present in 32% (19) of the 60 who remitted below major depression by 15 months. The pattern was of mild but typical depressive symptoms. Residual symptoms were more common in subjects with more severe initial illness, but were not related to any other predictors, including longer prior illness, dysthymia, or lower dose of drug treatment during the illness episode. There were weak associations with personality that might have been consequences of symptom presence. Residual symptoms were very strong predictors of subsequent early relapse, which occurred in 76% (13/17) of those with residual symptoms and 25% (10/40) of those without.