This report describes a case of aseptic meningitis induced by the tumor necrosis factor-alpha inhibitor infliximab. The patient, a 51-year-old female, was being treated for Crohn's disease. After an infliximab infusion, she had headache, fever, arthralgia, myalgia, and meningismus. Cerebrospinal fluid analysis was remarkable for a neutrophilic pleocytosis and elevated protein. Other potential causes of meningitis were excluded. Her symptoms completely resolved within 24 hours of presentation. Because infliximab commonly causes headache and is very immunogenic, we infer that infliximab-induced meningitis is immune-mediated and underrecognized. Potential risk factors and means for minimizing its occurrence are offered.