Background: We aimed to verify safety and effectiveness of certoparin real-world use and to identify predictors of thromboembolic events or bleeding. Methods: This was a non-interventional study documenting patients at hospital-or office-based physicians. Results: Patients' (n = 1407) mean age was 53.7 +/- 16.1 years. Reason for certoparin use was prophylaxis of venous thromboembolism in 1331 (94.6%) patients and treatment in 76 (5.4%) patients. In only 11.4% of those receiving prophylaxis and 13.2% of those receiving treatment dosing, duration and schedule of certoparin were within label. There were 2 patients with deep venous thrombosis (DVT], no pulmonary embolism PE]), and 51 patients (3.8%) with minor (nonmajor) bleeding complications in patients receiving prophylaxis. Two patients treated with certoparin had recurrent DVT and one had PE (one patient with minor bleeding). Conclusions: Certoparin is very effective in real world. This also applies to patients in whom clinical decision making leads to an alteration of recommended application.