Background Metabolic syndrome (MS) is a well-known risk factor for the development of cardiovascular (CV) disease; yet, controversy persists whether it adds incremental prognostic value in patients with established CV disease. Objectives This study was performed to determine if MS is associated with worse CV outcomes in patients with established CV disease treated intensively with statins. Methods We performed a post hoc analysis of the Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides and Impact on Global Health Outcomes trial, in which patients with established CV disease and atherogenic dyslipidemia (n = 3414) were randomly assigned to receive extended release niacin or placebo during a mean 36-month follow-up, to assess whether the presence of MS or the number of MS components contributed to CV outcomes. Results The composite primary end point of CV events occurred in 15.1% of patients without MS vs 13.8%, 16.9%, and 16.8% of patients with MS in the subsets with 3, 4, and 5 MS components, respectively (corresponding adjusted hazard ratios 0.9, 1.1, and 1.1 relative to patients without MS), P =.55. Comparing subgroups with 3 vs 4 or 5 MS components, there was no significant difference in either the composite primary end point or secondary end points. Patients with diabetes mellitus had higher event rates, with or without the presence of MS. Conclusions The presence of MS was not associated with worse CV outcomes in the AIM-HIGH population. The rate of CV events in statin-treated Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides and Impact on Global Health Outcomes patients with MS was not significantly influenced by the number of MS components.