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Background and Objective: Hemodialysis is one of the common therapulic proceduce for terminal renal failure. Insufficient and low efficient hemodialysis increases the mortality rate, therefore the assessment of hemodialysis efficacy is important. This study was done to determine the hemodialysis efficacy based on urea reduction ratio (URR) model and kt/v (Clearance Time Volume) criteria in Gorgan, Northern Iran. Materials and Methods: In this descriptive and analytical study 113 heomdilysis patients were selected prior to hemodilysis and five minutes after pump stopping, arterial blood urea nitrogen (BUN) was measured and then kt/v and URR were calculated. Also kt/v relations with weight, gender, educational level, length of hemodialysis session, blood flow rate, TMP (Terans Membran Presure), filter Ku/f (Clearance Ultrafiltration), preliminary disease, time of hemodialysis per week and the type of vessel access were determined. Data analyzed using SPSS-13 and independent t-test, chi-square, fisher exact test and Pearson correlation coefficient. Results: The mean of hemodilysis history was 37 months and mean of Patient's ages were 51.6 years. 77.9% of subjects had hemodialysis efficacy according to Kt/v and URR critrial. There was a statistical significant correlation between hemodialysis efficacy and time of hemodialysis session, blood flow rate, time of hemodialysis per week and type of vessels access (P<0.05), but there was not any significant correlation between hemodialysis efficacy and weight, gender, education, TMP, filter Ku/f and preliminary disease. Conclusion: This study suggested that hemodialysis efficacy in this center was better that other studies in Iran.