Aim: The operative correction of the hallux valgus deformity is a frequently performed procedure. However, the exact rate of postoperative deep vein thrombosis is unknown. We performed a prospective, phlebographically controlled study to quantify the rate of postoperative venous thrombosis following operative hallux valgus correction and to evaluate the need of a medical thrombosis prophylaxis. Methods: Consecutive patients undergoing subcapital osteotomy of the þrst metatarsal bone for correction of hallux valgus deformity were included in the study. Patients with clinical or hematological risk factors for venous thrombosis were excluded from the study. One hundred patients with a mean (±SD) age of 48.9±13.9 years were operated on and they did not get a medical thrombosis prophylaxis. At a mean (±SD) of 27.8± 4.1 days postoperatively, all patients were assessed by using phlebography. Results: The rate of postoperative venous thrombosis was four percent (four patients). The mean (±SD) age of the patients in the thrombosis group was 61.7± 6,1 years and in the no thrombosis group the mean age was 48.4± 13,9 years (p=0.034). Conclusions: Patients following hallux valgus surgery are at a low risk of venous thrombosis but the need of a medical thrombosis prophylaxis should be calculated individually for each patient according to the known levels of risks. A routine thrombosis prophylaxis might be justiþed for patients with risk factors and particularly for patients over sixty years of age.