OBJECTIVES: Orthopaedic surgery is one of the highest risk factors for venous thromboembolism.The main objective of this retrospective database analysis was to determine direct medical costs for pulmonary embolism (PE) in patient undergoing orthopaedic surgery in Slovakia from the payer perspective. METHODS: A retrospective database analysis of biggest health insurance company in Slovakia was conducted. Resources used and their respective costs in connection with PE were collected for patients undergoing elective total hip replacement (THR) or elective total knee replacement (TKR) during the period from January 1, 2007 till January 1, 2008. All resources and costs were categorized in four groups: inpatient, outpatient, drugs and examinations. Costs in Euro were calculated with official exchange rate 30,126 Sk/€. Cost comparison between groups of patients with PE and without PE after orthopaedic surgery was done. RESULTS: The group of 3069 patients (1121 men and 1948 women) after elective orthopaedic surgery was analyzed. There were 2153 patients with THR and 916 with TKR.  The average age was 64.5 and 68.4 years in THR and in TKR group respectively. Eighteen cases of PE were identified in the whole group (11 in THR and 7 in TKR). Average direct medical costs for group of patients were €5964 with PE and €3170 without PE. There was a following structure of costs (WITH and WITHOUT pulmonary embolism): 1) inpatient: €5064 and €2516; 2) outpatient:  €171 and €141; 3) drugs: €339 and €251; and 4) examinations: €390 and €262. CONCLUSIONS: Average direct medical costs for patients with PE after elective orthopedic surgery are €5964. This is almost 90% more then the average direct medical costs for patients without PE. Main driver of increased costs is inpatient stay at intensive care unit and at internal medicine department after episode of pulmonary embolism.