Introduction: End-stage renal disease (ESRD) is one of the health problems in today's world. Neuropsychological problems are more common in hemodialysis (HD) patients than in healthy individuals. Objectives: The aim of this study was to investigate the effect of long-term HD on memory function of these patients. Patients and Methods: Our study, included 80 HD patients of whom 39 were under 6 months of HD and 41 patients as another group which had a history of HD more than 6 months. Results: The population had a mean age of 51.60 years old (27.5% female). The scores of patients who have been hemodialyzed for a long-time (median time of HD was up to 4 years) had lower score in forward digit (FD), backward digit score test (BD), letter digit modality task (LDMT), letter symbol digit modality task (LSDMT) (5.49; 3.61; 21.12; 17.66) than the HD patients who underwent HD for a shorter term, with the median time of 3 to 5 months (7.38; 4.79; 39.77; 43.38) (P < 0.001). Conclusion:The present study demonstrated that end-stage HD patients who were under HD for a long time had significantly lower scores in the memory and attention tests. However, additional researches are needed in this area. ABSTRACTImplication for health policy/practice/research/medical education: ESRD patients who were under HD for a long time had significantly lower scores in the memory and attention tests. Please cite this paper as: Alidadi A, Bakhshani NM, Sabayan B, Ansari-Moghadam A. Evaluation of attention and memory function in hemodialysis patients; a study based on hemodialysis duration. J Nephropathol. 2020;9(3):e28.