Quality of life (QOL) has recently been explored as one of the main outcomes of renal replacement therapy. In this study, we sought to compare three groups of patients-hemodialysis, peritoneal dialysis, and transplantation-with regard to QOL. Methods. Seventy-five hemodialysis, 41 peritoneal dialysis and 20 transplant patients were given Patient Information Form, Short Form Health Survey 36, Beck Depression Inventory, and State-Trait Anxiety Inventory. Results. The QOL scores of the three groups were similar and lower than the normal Turkish population. Depression and anxiety levels had significant and negative effects on QOL of hemodialysis and peritoneal dialysis, but not transplant patients. In a multiple regression analysis, being male, being older than 46 years, living with family, having middle-higher income, having renal disease for a longer time, having a longer period of dialysis treatment, having comorbid illness, having not enough illness knowledge, and having higher levels of depression and of anxiety significantly correlated with a worse quality of life. Conclusions. The three forms of renal replacement therapy did not differ with regard to QOL. Among the factors that seem to affect QOL, psychological status and treatment/ illness knowledge had the most significant correlation. The underlying mechanisms need to be clarified.