The study’s purpose was analysis of influence of acid-base balance disorders during 30 minutes of reperfusion and during 4 hours after operation on graft early function in patients after kidney transplantation. The examined group consisted of 44 recipients: 20 men, 24 women in average age 47+-14 years. The blood sample for gas analysis was taken 9 times during operation using catheter placed in arteriovenous fistula 0, 1, 3, 5, 10, 15, 20, 25, 30 minutes after unclamping renal vessels. The evaluation of temporary acid-base balance state was made on the basis of common parameters: pH, pCO2, [HCO3-], BE. Examined patients were in general anesthesia with stable external conditions (O2 saturation, heart rate, blood pressure, temperature), also with constant tidal volume and rate. Parameters were recorded using Ohmeda and Dräger apparatus and Corning analyzers. Evaluation of graft function was based on amount and start of urine output as well as serum concentrations of creatinine, urea, uric acid and ions (Na, K). Parameters were analyzed during postoperative hospitalization and during 1-year observation period. Additional parameters like blood morphology, urinalysis, serum concentration of glucose, aminotransferases, ions (Cl, Ca, P) were also taken into consideration. The analysis showed increasing parameters of metabolic acidosis with compensatory blood pCO2 growth. Some alterations in vital parameters were observed, especially heart rate and blood pressure. Postoperative acid-base balance was also characterized by metabolic acidosis corresponding with initial state and course of reperfusion. Examination of graft condition and its function showed that dynamics of perioperative acid-balance disorders may play a role of delayed graft function risk factor. The amount of decreasing [HCO3-] may be the indicator of post-reperfusion kidney injury, which influence early and late graft function.