Objective: The objective of the analysis was to evaluate impact of adherence to lipid treatment guidelines [National Cholesterol Education Program's Third Report on Detection, Evaluation, and Treatment of High Blood Cholesterol and Adult Treatment Panel's (NCEP-ATP III)] on stroke events in managed care patients. Methods: Patients with laboratory values for low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), & triglycerides (TG) between January 1, 2003-December 31, 2005 [index date], no lipid therapy 6-months pre-index date, and minimum 12 months health plan eligibility pre- and post-index date were analyzed using a large integrated United States managed care database. Patients were classified as appropriately (AM) or inappropriately managed (IAM) using baseline lipid levels and the first post-index follow-up lipid panel (goal attainment irrespective of therapy), and risk stratification per NCEP-ATP III guidelines. Post-index, stroke event incidence between groups was analyzed descriptively and through a multivariate logistic regression analysis after controlling for differences in baseline clinical and demographic variables. Results: Among 8176 study patients (3493 AM; 4683 IAM), AM patients were significantly older [51.4 ± 9.1 and 50.0 ± 9.6 years, p<0.01] and comprised of fewer males (43.2% vs. 56.2%; p<0.01). AM patients were more likely to be at lower risk status at index date versus IAM patients (63% vs. 28%; p<0.01), and had a significantly lower Deyo-Charlson comorbidity score (0.32 ± 0.56 vs. 0.20 ± 0.44; p<0.01). During follow-up, fewer AM patients experienced a stroke event versus IAM patients (0.7% vs. 1.1%; p=0.03) and thereby were 36% less likely to have a stroke event (OR: 0.64, 95% CI: 0.44-0.93; p<0.01). Conclusion: Adhering to clinical guideline treatment recommendations was likely to be associated with subsequent stroke reductions and possible long-term cost savings in this managed care population.