Neurological involvement in Wegener's granulomatosis was studied by reviewing the charts of 324 consecutive patients in whom the diagnosis was made at the Mayo Clinic. One hundred nine patients (33.6%) had neurological involvement. Peripheral neuropathy occurred in 53; cranial neuropathy, in 21; external ophthalmoplegia, in 16; cerebrovascular events, in 13; seizures, in 10; cerebritis, in 5; and miscellaneous involvement, in 25. The mean age and sex ratio were similar in the patients with and those without neurological involvement. Among the patients with peripheral neuropathy, 42 had mononeuropathy multiplex; 6, distal symmetrical polyneuropathy; and 5, unclassified peripheral neuropathy. Multiple mononeuropathy was a major presenting symptom in 8 patients. A significantly higher percentage of patients with peripheral neuropathy, compared to those without peripheral neuropathy, had kidney involvement (p < 0.001). The second, sixth, and seventh cranial nerves were most frequently affected. Multiple cranial nerves were affected in 8 patients. Unusual neurological manifestations in the miscellaneous group were spastic paraparesis, temporal arteritis, Horner's syndrome, and papilledema.