The authors report two cases of gynecologic malignancy in women receiving different thromboprophylactic regimens. Presently, everyday clinical problems are not always solved based on the well-established standards for the preventive management in venous thromboembolism. The paper presents a review of the literature on the principles for the use of lowmolecular- weight heparins in patients undergoing oncologic surgeries, with particular attention to the aspects of thrombotic risk and suggestions on non-standard management in cases not included in the guidelines. The recommendations of scientific associations, due to their inertia, are released with a delay relative to research, and may present inconsistent views due to the differences in publication timing. This article is to raise readers’ awareness of the scale of the problem and the importance of the effects of thromboembolic complications on prognosis in cancer. The need to assess the risk of these complications at every stage of cancer treatment should be emphasized. Additionally, risk assessment can be used as an opportunity to educate patients in this aspect.