OBJECTIVE: To estimate the effects of increasing gas prices on mortality. METHOD: We developed a simulation-based partial equilibrium model that estimated the public health effects of a 20% rise in gas prices. Estimates on price elasticity for gasoline, price elasticity of motor vehicle crashes, relations among gasoline use, air pollution, and mortality were drawn from literature in economics, epidemiology, and medicine. RESULTS: For sustained 20% increases in gasoline prices over 1 year, and assuming other prices and factors were constant, we estimated: 1994 (range, 997 to 4984) fewer deaths from vehicle crashes and 600 (range, 300 to 1500) fewer deaths from air pollution. Combining both, we estimated 2594 fewer deaths. A Monte Carlo simulation involving varying assumptions on elasticities and relations indicated that 95% of the combined reduction in deaths was between 1747 and 3714. CONCLUSION: Results suggest that high gas prices have public health implications.