Aim: The article considers the results of research of the vascular endothelial growth factor (VEGF) in blood serum in patients with kidney and bladder tumors after surgical intervention. Materials and methods: The total of investigated patients consisted of 75 primary patients with kidney cancer (stages pT1-pT3N0M0), 75 patients with non-muscle-invasive bladder cancer (NMIBC), stages pTa-1NxMoG1-3, 25 patients with cysts of kidneys and 30 healthy patients. Results of research of content of VEGF in patients with kidney cancer and NMIBC in the postoperative period confirmed the role of angiogenesis processes both in the development of tumoral tissue and relapses of disease. Conclusion: Investigations of VEGF in blood serum may be additional method of revealing kidney cancer and NMIBC after surgical treatment of relapses of disease and may influence on the duration of recurrence-free period