Introduction: Independent from three classic Wirchows factors for deep venous thrombosis (stasis, hypercoagulability and changes in venous wall), there is several other factors that can, in different ways, promote development of DVT. They are well documented, thus the mechanism of every factor is not clear in every detail. Objective: The aim of our work was to check frequency of several risk factors among our DVT patients treated in our Institute and to evaluate their respective significancy. Methods and material: We have take anamnestic data from patients with DVT treated in our clinic in period 12/1999-12/2000. This data included previous thrombosis, concomitant malignant disease, therapy with estrogenes and smoking. Total count of patients was 88 (M 47, F 41). Average age was 55 with SD 14,99. RESULTS: We had 41 patients with iliacofemoral thrombosis, 41 patients with crural thrombosis, 4 patients with brachio-subclavial thrombosis and 2 patients with jugular thrombosis. 18 patients had history of previous vein thrombosis, 18 patients with concomitant malignant disease, 38 patients were smokers and in only one case (out of 47 male patients), we could link DVT with taking of estrogenes. Conclusion: We have found that history of previous vein thrombosis and malignant disease are significant factors for development of DVT. From the other side, we could not proove smoking as risk-factor for DVT because of its widespreading in the population. We had too small group of DVT patients taking estrogenes, so we could not assess significancy of estrogene therapy as risk-factor for DVT.