OBJECTIVES: An efficient assignation of resources in the service of hemodinamy requires the knowledge of costs of possible diagnostic procedure's combinations. Currently, in Mexico the costs for these procedures are very general and incomplete. The objective of this study was to estimate the direct and indirect medical cost of different interventionist cardiology diagnostic procedures that are practiced in the hemodinamy service in the Cardiology Hospital “Centro Nacional Siglo XXI” in Mexico City. METHODS: Identification of resource use at the hemodinamy service was realized through expert opinion and the revision of hospital records during the first two months of 2005. Unitary costs were obtained from the Accounting Department of the hospital. The intervention's cost estimation was realized with the technique “case mix” and the perspective was that of the Social Security Mexican Institute (IMSS). The direct medical costs included: material of high specialty, medical instruments, drugs, cinefluorscopy and human resources. Indirect medical costs included: equipment, depreciation, laundry, electricity, telephone, water, etc. Within the estimations of the interventions it was included the use of counterpulsation balloon, cutting balloon, glucoproteins (tirofiban or abciximab) and trombectomy. RESULTS: Diagnostic catheterism was estimated in US$328.7. The cost of the other interventions shifted in function of the type of the stent used (conventional or medical). Intervention of one vessel with conventional stent resulted in US$1182.5; and with medical stent this raised to US$3438.5. Also, intervention costs of one vessel trombectomy + counterpulsation balloon + glucoproteins inhibitors resulted in U$7508.1. An intervention with two left vessel was calculated in US$10,910.2 and with two left vessel and one right vessel, the cost increased to US$13,706.7. CONCLUSIONS: Our study results showed high direct medical costs heterogeneity on diagnostic procedures in a Mexican hemodinamy service. These results are useful for cost containment policies and for further health economics researches in Mexico.