Introduction The incidence of early deep venous thrombosis (DVT) following varicose vein surgery (traditional open stripping) with routine use of a tourniquet remains unknown. Materials and methods A retrospective analysis of all patients who underwent varicose vein surgery with a tourniquet in the authors' unit between 1 January 2012 and 30 November 2013 was undertaken. Cases of postoperative DVT were identified from the unit database, and re-assessments conducted 1, 3 and 6 months after the initial diagnosis were recorded from the outpatient department. Results Out of 1461 patients, 113 (7.7%) developed postoperative DVT. Nineteen (1.3%) patients had proximal DVT, and 94 (6.4%) patients had isolated distal DVT. The risk factors for postoperative DVT included old age (≥ 65 years), female sex and gastrocnemius vein dilation (GVD). GVD was found to be a significant independent risk factor for the occurrence of DVT, with an odds ratio of 2.437 (95% confidence interval 1.644-3.611). Five patients with distal DVT (5.7%) and eight patients with proximal DVT (44.4%) still exhibited a thrombus at 6-month follow-up, but with decreased size and at various stages of resolution. Conclusions This study found a higher incidence of postoperative DVT (7.7%) with routine use of a tourniquet during varicose vein surgery than has been reported previously. Among the factors examined, GVD had the highest predictive power for postoperative DVT. Both distal and proximal DVT were associated with acceptable outcomes.