Introduction: Dialysis is a time consuming procedure. Due to conflicting results in recent reports about depression and quality of life in Hemodialysis and CAPD patients, in order to determine the prevalence of depression, the present study was performed on Hemodialysis and CAPD patients who were referred to the dialysis ward in the Imam Hossein Hospital of Tehran in 2003-2004.Method and materials: A cross- sectional study was carried out. Case groups were selected from Hemodialysis and CAPD patients. Prevalence of depression was measured by Beck depression inventory (cut of point = 15).Results: The study was conducted on 44 Hemodialysis and 19 CAPD patients. Two groups were matched in age, sex, marital status. The number of patients with depression in Hemodialysis and CAPD were 26 (59.1%) and 11 (57.9%). The results in two groups were analyzed by Chi- square Test. No statistically significant differences were detected between two groups in depression symptomatology.Conclusion: Due to high prevalence of depression among two groups of patients, appropriate diagnosis and treatment of depression, in order to improve the quality of life, is recommended.