Background: Nasopharyngeal cancer (NPC), a highly prevalent malignant disease is a leading cause of death in several regions in Southern China including countries in Southeast Asia. In Indonesia, NPC is a major multi-ethnic problem and it remains one of the most confusing and commonly misdiagnosed disease until advanced stages. Chemotherapy improves treatment but also contribute towards increased risk of thrombosis in cancer. Methods: A total of 12 subjects (males n=8; Stage II n=2; Stage III n=2, Stage IV n=8) were recruited into the study. Blood sampling was performed at pre- and post-chemotherapy cycles 1 to 3 followed by radiotherapy. PT (INR), aPTT, TT ratios were determined together with D-dimer, platelets and platelet aggregation. Results: The mean age of NPC patients was 43.3 ±9.0 years. Pre-chemotherapy ratios of PT, aPTT and TT were <1.0 which indicated a hypercoagulable state. No significant variation in these parameters were seen post-chemoradiotherapy except that D-dimer were elevated postradiotherapy and platelet numbers significantly reduced from cycle 2. However, 4 patients (33.3%) with Stage IV disease had D-dimer levels above the normal level (<500 ng/mL) at post-radiotherapy were further analysed. This suggest a further enhanced hypercoagulable and hyperfibrinolysis state and thromboembolic risk following radiotherapy in this small cohort study. Conclusion: Chemoradiotherapy enhance the risk of thromboembolism in 33.3% of advanced NPC patients in this small study group. These findings indicate that not all NPC patients show enhanced risk of thromboembolism following chemoradiotherapy.