Cancer patients are at higher risk for venous thromboembolism (VTE). Anticoagulants, when used for prophylaxis, had successfully reduced the incidence of VTE in high risk patients. Nevertheless, many registry studies have shown low compliance rate with published prophylaxis guidelines. From January 2004 through June 2008, hospital database was searched for all discharge diagnoses of cancer with deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Prophylaxis rate for the whole group and for subgroups in relation to recent hospitalization, duration of cancer diagnosis and number of other coexisting risk factors were studied. Two hundred patients were identified; majority (91.8%) had advanced-stage cancer at time of VTE diagnosis. In addition to cancer, many patients had multiple coexisting risk factors for VTE with 137 (68.5%) patients had at least three while 71 (35.5%) had four or more. Overall, 111(55.5%) patients developed lower-extremity DVT while 52 (26%) patients developed PE, other sites accounted for 18%. Majority of the patients (72%) had VTE diagnosed within the first 12 months following cancer diagnosis. Almost three quarters of the patients (73.5%) had not received any antecedent prophylaxis. Prophylaxis rate was 23% among patients with ≥ 3 risk factors and 50% among the highest risk group with ≥ 5 risk factors. Based on our findings, majority of VTE in cancer patients occurred due to failure to offer prophylaxis, minority were due to prophylaxis failure. Meticulous quality improvement programs should be established to emphasize the importance of implementing more intensive prophylaxis among high-risk cancer patients.