The effectiveness of federal automobile safety standards was examined using detailed data on 236,000 vehicles in fatal crashes in the United States during 1975-1978. Controlling statistically for type of regulation, types of vehicles, and ages of vehicles, the federal motor vehicle safety standards were associated with substantial reductions in car occupant death per 100 million vehicle miles travelled, and some reductions in fatal collisions of the federally regulated vehicles with pedestrians, motorcyclists, and bicyclists. Some 37,000 fewer deaths occurred in 1975-1978 than would have been expected without the federal standards.