This is a report on an outbreak of cattle poisoning by Stryphnodendron rotundifolium var. villosum (Benth.) Scalon in the state of Goiás in Brazil. In a herd of 80 cattle that consumed the mature fruit of this plant that was present in their pasture, 12 animals fell ill and died. The clinical signs that they presented were apathy, progressive weight loss, reeling, bristling, and dry stools containing seeds. The main necropsy findings were jaundice, an increased lobular pattern and orange coloration in their liver, enlarged kidneys with yellowish medullae, and pre-stomachs containing fruit peels and seeds. A histopathological examination revealed vacuolar degeneration and necrosis in the liver and kidneys and vacuolar degeneration in the rumen, omasum, reticulum, and intestine. The diagnosis of poisoning by S. rotundifolium var. villosum was based on epidemiological data, clinical findings, and pathological changes. Our results can aid in the differentiation between poisoning by S. rotundifolium var. villosum and poisoning by other toxic plants that are of interest to lifestock.