A bovine cerebellar disorder of recurrent seizures characterized by loss of equilibrium, extension of the head and thoracic limbs, opisthotonus, nystagmus and falling to the side or backwards is described from 16 farms in the Brazilian state of Rio Grande do Sul. The main pathologic features were vacuolation, degeneration and loss of Purkinje cells with axonal spheroids in the cerebellar granular layer and white matter. Electron microscopic study of Purkinje cells showed cytoplasmic membranous bodies, similar to those observed in human and animal gangliosidoses. Feeding trials in calves demonstrated that the disease is an intoxication caused by ingestion of Solanum fastigiatum var. fastigiatum. A hypothesis is proposed that the intoxication is an induced lysosomal storage disease, probably a gangliosidosis.