Objective: This study examined associations between pre and post stroke statin use with health care costs among elderly stroke survivors enrolled in a Medicare Health Maintenance Organization (HMO). Methods: This was a retrospective analysis of Medicare HMO in the southeastern region of United States. Stroke survivors were identified using primary inpatient discharge codes of 434.xx or 436.xx during the ‘enrollment period' from January 1, 2000 to December 31, 2002. Patients were required to have at least 2 prescription fills for HMG-CoA reductase inhibitors (statin) and continuous eligibility to the HMO benefits during index period. Medication adherence was calculated using prescription refills. Multivariate log-linear regression analyses were used to determine predictors of health care costs. Results: A total 181 stroke patients with mean age of 74.3 years (SD=7.6) and over 60% were studied. Over 55.2% patients were on atorvastatin, followed by simvastatin with 24.3%. The average medication possession ratio for statins was 49.6%. Patients reported poor health status and significant comorbidity. In multivariate log-linear regression analyses factors, we found that statin use in the year prior to stroke (27% of the patients) was significantly associated with decreased health care costs (p<0.05). The only other factor significantly associated with increased health care costs in the post-stroke year was increased comorbidity severity (p<0.001). Conclusion: Statin use in elderly HMO enrolled elderly patients in the pre-stroke period was significantly associated with significant reductions in health care utilization and costs in the post-stroke year. Prophylactic statin use in elderly patients at risk for stroke may be warranted to decrease post-stroke morbidity resulting in significant health care costs.