BACKGROUNDEscalating healthcare cost is a challenge in public health sector for financial manager. Choosing an appropriate accounting method is necessary for cost containment. In present study, we applied the time driven activity-based costing method to assess the cost in performing a computed tomography in a teaching hospital.The objectives of this study are: 1) To describe the application of Time Driven Activity-Based Costing (TDABC) to Computed Tomography (CT) scanning unit; 2) To obtain the cost of unused capacity of personnel and idle time cost of CT scanner; and 3) To appraise the evidence of benefits of such tools in health sector and its efficiency.