Fusarium torulosum was isolated consistently from the leaves of kikuyu plants collected from a pasture near Maitland, NSW, on which grazing cattle had been affected by kikuyu poisoning. This fungus is known to produce the toxins wortmannin and butenolide, both of which can produce clinical signs and pathological changes similar to those exhibited by cattle with kikuyu poisoning. The available evidence suggests that F. torulosum might be the casual agent of kikuyu poisoning in Australia.