Kidneys are tubular organs located on both sides of the spine in the retroperitoneal space and they are covered with muscle, fat capsula and ribs. Kidneys have red-blue color nad they have a smooth surface. Shape is most similar to the grain beans. Acute kidney injury and chronic kidney failure are the most common causes of renal failure. Monitoring of proteinuria and GFR determines the condition and function of the kidney. If GFR is less than 15ml / min we are talking about kidney failure and the patient has to be subjected to hemodialysis, peritoneal dialysis, and transplantation when appropriate donor is found. The histocompatibility of the MHC molecule and the HLA antigen with a given dose of immunosuppression is a prerequisite for successful transplantation. After the operation vascular and urological complications may occur. Bleeding, lymphochelas, arterial stenosis, pseudoaneurysms and intrarenal A-V fistulas, artery and vein thromboses are most commonly vascular complications. Urological complications include obstruction with consequent hydronephrosis and urinary fistulas. Complications are most commonly observed shortly after surgery but may occur for several months to a few years after transplantation. Early detection with ultrasound or CT is crucial for successful resolution of the complications. Surgical complications are now treated with minimally invasive methods such as endoscopic, laparoscopic and percutaneous procedures.