Acute rejection (AR) is one of the most important problem in renal transplant recipients. Identifying high risk patients for AR can help us to detect AR episodes timely. We examined 115 consequtive renal transplant recipients. first 24 hours urine volume (1th 24h UV ) was recorded, patient followed for one year. Any AR that confirmed by biopsy was recorded. Patients were devided in to two group in respect to 1th 24h UV. G1 consist of patients with 1th 24h UV less than 12 lit and G2 consist of patients with 1th 24h UV more than 12 lit. Two group were compared in respect to AR episodes and need to dialysis in first year after transplantation.from 115 patients 49 were males and 66 females. Mean age at transplantation was 36.5.there was no significant difference between two groups in respect to underlying renal diseases. There was significant difference between two groups in respect to AR episodes (p=0.008). And there was significant difference between two groups in respect to need to dialysis (p=0.005). First 24 hours post transplant urine volume may be use as a prognostic risk factor for AR and early graft loss in renal transplant recipients.