An all-terrain vehicle (ATV) is a motorized vehicle designed for off-road use with low-pressure tires, a seat that is straddled by the operator, and handlebars for steering. Currently, only four-wheeled models are produced in the United States; production of three-wheeled ATVs ended in 1987 because of safety concerns. During the 1990s, West Virginia led the United States in per capita deaths from ATV crashes, with rates approximately eight times higher than the national average. In an attempt to curtail this trend, West Virginia enacted legislation in 2004 to regulate ATV use. This law prohibited ATV operation on paved roads with a center line, unless the vehicle was traveling a distance of < or =10 miles and at a speed of < or =25 miles per hour. The statute also required helmet use and training for ATV riders aged <18 years, regardless of where the ATV was ridden. To guide further prevention campaigns and identify appropriate populations for targeted educational interventions, the West Virginia Department of Health and Human Resources used data from death certificates of 1999-2006 ATV fatalities to analyze demographic and socioeconomic trends. Trends by age and crash classification (i.e., traffic versus nontraffic) also were evaluated in the context of the 2004 law. Results of that analysis indicated that, after the ATV law was enacted in West Virginia, the ATV-related death rate in the state among children did not decline, and total ATV-related traffic fatalities increased from 0.72 per 100,000 population in 2004 to 1.32 in 2006. Higher annual ATV death rates occurred among males, persons aged 10-17 years, residents of the most impoverished counties, and persons aged > or =25 years who had not completed high school. Further preventive measures aimed at reducing ATV-related fatalities should be considered, such as targeted educational interventions and more stringent provisions of the law.