BACKGROUND: Deep venous thrombosis (DVT) of the lower extremity causes a major disease burden globally. Currently, oral anticoagulant therapy is used as the first-line treatment of DVT, however, medication non-adherence remains a serious problem for postoperative spinal surgery patients whose DVT incidence is at a high level. AIMS: To explore barriers and facilitators affecting patient oral anticoagulant medication adherence, based on guidance using the COM-B model. METHODS: This study was a qualitative study using a descriptive research design with in-depth and semi-structured interviews. Data were analyzed adopting traditional content analysis methods. RESULTS: Based on the COM-B theoretical model, we identified 9 barriers and facilitators from capability, opportunity, and motivation domains. CONCLUSIONS: Patients were confronted with barriers from capability, opportunity, and motivation domains, which were not isolated but interrelated. Future interventions should incorporate facilitators and barriers to address medication adherence issue with a holistic approach at multiple levels.