Diesel engines power the dominant share of goods movement, construction equipment, and public transport vehicles in the global economy. This report presents a global strategy to reduce fine particulate (PM2.5) and black carbon emissions from the global fleet of on-road diesel vehicles. The strategy identifies 36 countries for immediate action. These actions include: changes to specifications of imported fuels, changes to specifications of refined fuels, adoption of emission standards for new vehicles, and city-based introduction of cleaner fuels and vehicles in targeted fleets. Successful implementation of the strategy would prevent an estimated 500,00 annual premature deaths in the year 2050. The estimated benefits of this strategy would exceed projected costs by a factor of 16.