Risk factors of venous thromboembolism are acquired factors such as obesity, hormonal contraceptives, immobilization, and thrombophilia. Their combination leads to an increased risk of venous thrombosis. Objective: The aim of the study was to investigate effect of high BMI on the risk of venous thrombosis in patients with thrombophilia. Material and methods. We examined 96 patients with thrombophilia (mean age 51.61 years, 42 women and 54 men) and 73 patients without mutations (mean age 41.12 years, 17 men and 56 women) with different BMI. The first group involved 31 patients with venous thromboembolism, the second group included 15 patients. Results. The combination of BMI > 25 kg/m2 and thrombophilia influences the risk of venous thromboembolism.