Venous thromboembolism (VTE) is a common cause of morbidity and mortality. The incidence in the general population is 0.117/year. Cancer patients carry a four-fold risk, increasing the annual incidence to 0.48/year. Breast cancer is one of the most common cancers and the second leading cause of cancer among women. In this review, we intend to present how breast cancer and its treatment contribute to the development of VTE and how this affects the prognosis. We also aim to clarify whether prophylaxis is indicated, and if so, in which subgroup of patients and under which conditions. Based on the current literature, breast cancer is associated with the lowest incidence of VTE among cancers, and thus the routine use of prophylaxis is not recommended. Nevertheless, the occurrence of VTE significantly affects the prognosis. The more advanced the stage of breast cancer, the greater the risk of VTE, although VTE is more lethal when it occurs in the early stages of breast cancer (BC). The risk of VTE decreases with time after the diagnosis. However, the later it occurs, the more it will affect the prognosis. The risk for VTE should be estimated for each patient and decisions should be individualized according to the general medical condition of the patient, other predisposing risk factors, the type and duration of surgery, the adjuvant treatment used and the past medical history of VTE. After surgery, early mobilization and stockings should be used. If the duration of the operation exceeds three hours, prophylaxis ought to be given. Prophylaxis should be considered in all cases with primary reconstruction. When it comes to adjuvant therapy, it is advisable to avoid the concomitant administration of chemotherapy and hormone treatment. Moreover, if not contraindicated, aromatase inhibitor (AI) should be preferred in postmenopausal women. In high-risk patients who will receive adjuvant treatment, prophylaxis can be considered for 3-6 months. Finally, due the interactions of the medications, low molecular weight heparin (LMWH) should be preferred to warfarin.