OBJECTIVES: To compare the resource use and subsequent costs associated with types of major bleeds among hospitalised acute coronary syndrome (ACS) patients. METHODS: Retrospective chart review was undertaken in Italy, France and Spain of patients hospitalised for ACS and receiving antithrombotic, antiplatelet or fibrinolytic therapy to identify individuals with retroperitoneal (RP), intracranial (IC), gastrointestinal (GI), puncture site or excessive surgical bleeds requiring 2 or more units of blood, or decrease in Hb > 3g/dL (DHb). Use of procedures and length of stay (LOS) were extracted from the records. Publicly available country unit costs were applied to estimate the cost of these major bleeds among ACS patients. RESULTS: A total of 117 patient records were included, 63.2% males, average age 74 years. Most patients were admitted for ST-segment Elevation MI. The LOS by type of bleed was 9-14 days in Spain compared to 7-13 in Italy and 5-10 in France. Only Spain identified records with bleed-related mortality. Most days were in coronary care or intensive care units. For procedures, CT scans were more common in Spain and ultrasound most common in France and Italy. Selected results show an average LOS ranges between 9-14 days for DHb (total costs €7097-9326); 9-13 days for transfusion (€8280-9105); 5-10 days for puncture site bleeds (€6182-10572). RP bleeds resulted in 5-7 days (€5761-8080) and GI bleeds in 5-13 days (€3906-9173). Overall average costs were €8341 for France, €6730 for Italy and €8027 for Spain CONCLUSION: The most frequently reported major bleeds in trials (DHb, puncture sites/transfusions) are more costly than expected. Costs associated with ACS-related bleeds vary by type and these specific costs should be used in analyses.