Rabies was confirmed by specific laboratory tests in an Eastern fox squirrel (Sciurus niger) which was shot in San Leandro, Alameda County, California, in August, 1971. The rabid animal had displayed aggressive, furious behavior. The one person who had been exposed, during an unprovoked attack, subsequently underwent antirabies treatment. Except in aberrant, isolated cases, such as described herein, rabies is only rarely diagnosed in rodents in the United States. Antirabies treatment for rodent bites is seldom justified, unless rabies has been demonstrated by reliable laboratory tests.