The aim of this study is to report an outbreak of pig rabies occurred in June of 2009 in Tocantins State, Brazil. The six affected pigs belonged to the same farm, a semi-extensive herd with 85 animals. All animals showed depression, incoordination, lateral recumbency, paralysis of posterior limbs, tremors and convulsions. Death occurred 48 hours after the onset of clinical signs. No notable changes were observed in the post-mortem examination and diagnosis of rabies was confirmed by the fluorescent antibody test and micebioassay from brain samples collected from two animals. This was the first confirmed case in Tocantins state and the largest outbreak of rabies in pigs described so far in Brazil.