The impact of religious involvement on time to remission of depression was examined in older medical inpatients with heart failure and/or chronic pulmonary disease (CHF/CPD). Inpatients older than 50 years with CHF/CPD were systematically diagnosed with depressive disorder using a structured psychiatric interview. Cox proportional hazards regression was used to examine the effects of religious involvement on time to remission, controlling for covariates. Of 1000 depressed patients identified at baseline, follow-up data on depression course were obtained on 87%. Patients involved in group-related religious activities experienced a shorter time to remission. Although numerous religious measures were unrelated by themselves to depression outcome, the combination of frequent religious attendance, prayer, Bible study, and high intrinsic religiosity, predicted a 53% increase in speed of remission (HR 1.53, 95% CI 1.20-1.94, p = 0.0005, n = 839) after controls. Patients highly religious by multiple indicators, particularly those involved in community religious activities, remit faster from depression.