The 1931 500 has been described as more of a demolition derby than a speed race, and the requirement of a riding mechanic had doubled the number of men whose lives were at risk.

When driver Joe Caccia crashed during practice, he and mechanic Clarence Grover were killed. During the race, Billy Arnold's car went over the wall in flames. Arnold and his mechanic, Spider Matlock, were seriously injured but survived. However, a wheel from their car flew out of the Speedway grounds and killed an 11-year-old boy playing in his front yard on Georgetown Road.

At the end of the grind, the victory went to Louis Schneider and riding mechanic Jigger Johnson.

Finishing 13th was Dave Evans, driving a Cummins, the first diesel- powered entry.