The USAC National Champion and Indianapolis 500 winner was Bobby Unser.

Mike Spence died in an accident while practicing for the 1968 Indianapolis 500.

Ronnie Duman died of burns suffered during the Rex Mays Classic.

Note 1: John Cannon, George Fejer, Lou Sell, Mark Donohue, Jack Eiteljorg, Bud Morley, Lothar Motschenbacher, Jochen Rindt, Graham Hill, Jack Brabham, Denis Hulme, Skip Scott and Peter Revson are not eligible for points.

Note 2: Ronnie Bucknum did not compete with a USAC license until after the events at Indianapolis Raceway Park.