The clinical and pathologic findings in 32 patients with central nervous system (CNS) coccidioidomycosis were studied. Seventeen patients had received more than 1.5 g of amphotericin B (AMB), chiefly intravenously, during treatment periods of up to eight years. Eight patients had received 246 mg to 1.3 g of AMB, and three patients had received only brief treatment (one to three days; total dose, no more than 100 mg). Fifteen patients had not received AMB. Significant clinical differences between the patients treated with and without AMB were longer survival time following diagnosis of illness (P less than 0.05) and more frequent cranial nerve signs in the treated patients (P = 0.089). The wide spectrum of macroscopic and microscopic lesions in the CNS included meningitis, ventriculitis, hydrocephalus, and cerebritis. Long-standing infections were associated with disseminated discrete foci of gliosis and infarcts in the brain, particularly in the basal ganglia and deep white matter, related to endarteritis obliterans in basilar meninges. In contrast to patients with CNS and systemic mycoses treated with amphotericin B methyl ester (J Infect Dis 146:125, 1982), no diffuse lesions of white matter were found in patients treated with or without AMB. Histopathologic patterns observed in this study included leptomeningitis alone, leptomeningitis with cerebritis, leptomeningitis with cerebritis and infarcts, and the unusual pattern of disseminated miliary granulomas. The frequency and extent of CNS lesions in the groups treated with and without AMB were not significantly different. It is concluded that AMB therapy, while prolonging survival, does not alter the spectrum of pathologic findings in CNS coccidioidomycosis infection.