Venous thromboembolism (VTE) is a frequent complication in surgical patients, with the potential for long-term disability or fatal outcome. The rationale behind routine use of thromboprophylaxis can be summarized in three points: (1) VTE is frequent in certain surgical populations, (2) VTE may be fatal, (3) thromboprophylaxis is highly effective and safe. In addition to these clinical benefits it has the potential for lowering overall treatment costs by preventing diagnostic procedures and delayed discharge or readmission due to thromboembolism. Surgical patients tend to have more than one risk factor for VTE, and in view of the fact that the effect of that risk is cumulative, it is important to stratify the risk to tailor an adequate prophylaxis strategy. There is consensus that heparins are both effective and safe in preventing VTE in surgical patients. Evidence-based local strategies should be available locally to clinicians and adhered to in order to maximize outcomes. Guidelines are intended to assist surgeons in making decisions in regard to DVT prophylaxis when performing surgical procedures.