BACKGROUND Recent studies provide conflicting evidence about the association of statin use and decreased efficacy of intravesical bacille Calmette-Guérin (BCG) therapy for bladder cancer. Because statin drugs have immunomodulatory properties that could reduce the effectiveness of BCG, we investigated whether concurrent use of statin drugs was associated with worsened clinical outcomes in patients undergoing BCG treatment for non-muscle-invasive bladder cancer. METHODS We retrospectively analyzed records of 120 patients undergoing BCG treatment during 1997 through 2007 at a single Department of Veterans Affairs Medical Center. Tumor-progression events, total recurrences, disease-specific and overall mortality were the outcomes relative to statin use. Fisher's exact, Student's t-tests, and logistic regression were used to compare the groups. RESULTS Among the 90 evaluable patients, there were no significant differences between groups with regard to tumor grade and stage distribution or smoking status. Statins were used during BCG therapy by 47.8% of patients. Comparing patients with no use versus use of statins, 8.5% versus 11.6% had local tumor progression (p = 0.44); 10.6% versus 9.3% underwent cystectomy, chemotherapy, or radiation therapy (p = 0.56); and metastatic disease developed in 6.7% versus 11.6% (p = 0.33). Of the 27 patients who died of any cause, 12.5% (2 of 16) versus 27.3% (3 of 11) in the nonstatin versus statin groups, respectively, died of disease (p = 0.32). CONCLUSIONS Concurrent statin use was not associated with adverse outcomes for patients undergoing BCG treatment for bladder cancer. While statins have a plausible biologic mechanism to reduce BCG efficacy, no differences were seen in this small pilot study.