Kidney transplantation is the most common and the most important method of end stage renal disease treatment. Evaluation of primary graft function after kidney transplantation in three groups of live unrelated, related and cadaveric donors. We retrospectively studied 130 KTP in a 16 month period. We have three groups of recipients: live unrelated (group I), live related (group II) and cadaveric (group III) donors. Volume of urinary output in first day after transplantation and renal functioning tests (serum urea, Creatinine, Na and K) in first week after transplantation were recorded and compared in three groups. We have 67 male and 63 female recipients. According to age and sex 67 patients (51.54%) were in group I, 16 patients (12.30%) in group II and 47 patients (36.15%) in group III. Mean first day urinary output in group I, II and III were 10621, 10884 and 6400 ml. This parameter in group III was significantly lower than others two groups. Decreasing in creatinine serom (<1.5 mg/dl) in first day, first week and first year were 7.40%, 59.25% and 81.25% in group I, 20%, 60% and 85.71% in group II and 5.12%, 38.8% and 67.56% in group III. There were no significant differences in renal function tests in three groups. Recipients of cadaveric kidney have the worst primary renal function and urinary output in first day after kidney transplantation.