Objective: Guidelines recommend 4 weeks of thromboembolic prophylaxis in patients who undergo major surgery for solid malignancies. However, there are limited head-to-head comparisons of risk of venous thromboembolic complications in patients with and without cancer undergoing similar surgical procedures. The purpose of this study was to compare risk of venous thromboembolic complications following major renal surgery and cystectomy between patients with and without cancer at the time of surgery. Material and methods: In the nationwide Danish National Patient Registry, which captures all hospital contacts, including surgical procedures, we identified 8,645 patients who underwent major renal surgery (4,273 without cancer and 4,372 with cancer) and 2,164 patients who underwent cystectomy (359 without cancer and 1,805 with cancer) in 2000–2009. The rate of venous thromboembolic events within 6 months from surgery was compared for patients with and without cancer after stratification on organ using Chisquared test. Results: There was no difference in the rate of venous thromboembolic complications within the first 6 months after major renal surgery (0.4% and 0.3% [p=0.91]) or cystectomy (1.3% and 0.8% [p=0.44]) for patients with and without cancer. The cost for 28 days of Tinzaparin 4.500 IE administered by the patient was €112, whereas the cost if administered by a community nurse was €1.988. Conclusions: Our study questions the different recommendations in thromboembolic prophylaxis between patients with and without cancer after major renal surgery and cystectomy.