BACKGROUND: Few studies have investigated the roles of religiosity and spirituality in predicting treatment response among psychiatric patients with depressive disorders. METHODS: In total, 232 outpatients with depressive disorders completed measurements of psychological symptoms, religiosity, and spirituality at baseline. A response was defined as Clinical Global Impression-Improvement scale (CGI-I) score of 1 or 2 at the last visit during a 6-month treatment period. Univariate analyses and logistic regression analysis were used to identify predictors of treatment response. RESULTS: In univariate analyses, treatment response was associated with marital status, longer treatment duration, less severe baseline symptoms, higher personal importance of religion, and higher spirituality. In logistic regression analysis, subjective important considerations for religion and spirituality were significantly related with treatment response after controlling for marital status, treatment duration, and baseline symptom severity. Of these variables, spirituality remained a significant predictor in the final model. CONCLUSIONS: These findings suggest that higher spirituality may independently contribute to favorable treatment responses among depressed patients in addition to other demographic and clinical factors.