OBJECTIVES:  Cardiovascular diseases are the leading cause of morbidity and mortality in the world. Coronary Angiography remains the corner stone in the management of CVD, and the gold standard for CAD diagnosis The Coronary Angiography is performed to diagnose the presence and severity of CAD. Globally, diagnostic cardiac catheterization ranks as the sixth most commonly performed healthcare procedure with total charges exceeding $4 billion annually. This high volume makes the Coronary Angiography a subject of interest to all healthcare manager, health economist and clinicians. The Objective of this study is to utilize the Step Down costing methodology for estimating the cost of Coronary Angiography at UKMMC.    METHODS: This is a cross sectional study, using random sampling with 303 patients who have undergone Coronary Angiography as inpatient at UKMMC, between January 2003 till December 2005. The sample is  grouped using International Refined DRG (IR-DRG) to assign DRG to each patient. Step down costing is done to cost these Coronary Angiography patients using Clinical Cost Modeling (CCM) software Ver. 2.1. Costing tool gives us the cost per day of stay in the Cardiology ward. Once related to the Length of Stay (LOS) cost of entire inpatient care episode were estimate. The cost of a procedure at the catheterization lab (CathLab) was calculated using the step down methodology. Cost of the inpatient Coronary Angiography is calculated by summation of CathLab cost and cost of inpatient episode of care.   RESULTS: Cost of Inpatient Coronary Angiography at UKMMC ranges from RM 1,007 to RM 16,697.26 (mean = RM 5,110.89, SD RM 2,798.06). Cost per procedure in CathLab is estimated to be RM 384. The total cost of treatment for 303 patients is RM 82,115.   CONCLUSIONS: Step Down Costing using the CCM is an easy way estimating the cost of one of the high volume procedure. This can help devising strategies for better utilization of scarce healthcare resources.