Ramaria flavo-brunnescens is a mushroom that grows in eucalyptus forests causing poisoning in cattle, sheep and, with less frequency, in horses and pigs. It causes ulcerative and gangrenous lesions in the skin, tongue and esophagus, and loss of hairs of the tip of the tail. Nervous signs are occasionally observed in sheep. This review aims to update the knowledge about poisoning by R. flavo-brunnescens in cattle and sheep in South America. Articles published as of 1950 were retrieved, and the epidemiological data, clinical signs, pathologies, and data on the pathogenesis of intoxication were reviewed including the most recent data on possible modes of action of the active ingredient(s) of R. flavo-brunnescens.