This study investigates a case of necrotizing meningo-encephalitis caused by bovine herpesvirus in São Paulo. The feedlot-raised calf presented cerebrocortical degeneration. Its ruminal hydrogen sulfide concentrations as well as those of nine healthy animals raised in similar conditions were inferior to 1,000 ppm. Cerebral spinal fluid analysis revealed pleocytosis. Sulphur concentrations in the water and diet were low, as well as hepatic and renal lead concentrations. Laboratory diagnoses of rabies were negative. The main histopathological evidence was telencephalic grey matter necrosis. Bovine herpesvirus type 5 DNA was detected by PCR analysis of formalin-fixed, paraffin-embedded brain tissue samples.