Background: The number of patients with chronic renal failure is increasing in Iran. Quality of life is an important indicator that reveals the sense of well-being, positive understanding of their, and the effectiveness of health care in patients undergoing dialysis, which could be affected by duration of dialysis. Objectives: This study aimed at investigating the relationship between quality of life and duration of dialysis in hemodialysis patients. Methods: In this descriptive correlational study, 246 patients with chronic kidney failure were selected by Single-stage stratified cluster sampling. Hemodialysis patients were put into 2 groups with a duration of hemodialysis less than and more than 36 months and were then compared with each other. The quality of life was measured using the kidney disease quality of life short form (KDQOL-SF36). Data analysis was performed by the Pearson correlation coefficient, independent t-test, and ANOVA Results: The mean duration of hemodialysis patients was 34.03 months. There was no significant relationship between the quality of life in patients and duration of hemodialysis. Poor quality of life had a significant correlation with old age (P < 0.001), educational level (P < 0.001), job, and income (P < 0.001). Conclusions:The findings showed poor quality of life in patients on dialysis. The length of the disease and other accompanying diseases reduced the quality of life in dialysis patients as their age increased. It is evident that educated people who have better access to sources of support and are able to cope with disease complications have a higher quality of life.