Meningioma is an intracranial tumor with few confirmed risk factors. Recent research points to an impact on meningioma risk from factors related to immune function and development, such as allergy, immunoglobulin E, and Varicella infection status. To further explore an association with immune function, the authors assessed individual seroreactivity to meningioma tumor-associated antigens among participants enrolled in a multicenter, population-based US case-control study of meningioma (2006-2009). Serum samples from cases (n = 349) and controls (n = 348) were screened for autoantibody reactivity to 3 proteins identified in previous studies: enolase 1 (ENO1), NK-tumor recognition protein (NKTR), and nuclear mitotic apparatus protein 1 (NUMA1). Case-control differences were not strong overall (adjusted odds ratio (OR)(ENO1 (continuous)) = 1.1, 95% confidence interval (CI): 0.6, 1.9 (P(trend) = 0.3); adjusted OR(NKTR (continuous)) = 1.3, 95% CI: 0.7, 2.4 (P(trend) = 0.02); and adjusted OR(NUMA1 (continuous)) = 1.1, 95% CI: 0.7, 1.8 (P(trend) = 0.06)); however, antibodies to NKTR and NUMA1 were detected at higher levels in cases than in controls, particularly among men (for men, adjusted OR(ENO1 (continuous)) = 1.6, 95% CI: 0.5, 4.7 (P(trend) = 0.24); adjusted OR(NKTR (continuous)) = 4.3, 95% CI: 1.2, 15 (P(trend) = 0.009); and adjusted OR(NUMA1 (continuous)) = 3.6, 95% CI: 1.1, 11 (P(trend) = 0.006)). These results indicate that men with meningioma commonly react with a serologic antimeningioma response; if supported by further research, this finding suggests a distinctive etiology for meningioma in men.