Background: All-terrain vehicle (ATV) sales have climbed 89% in the last 5 years. We sought to determine if pediatric ATV accidents have increased in frequency and morbidity. Methods: Medical records of children treated in our emergency unit for ATV accidents from 1993 to 2003 were reviewed. The 11 years were divided into 2 periods, January 1993 to June 1998 and July 1998 to December 2003, to allow comparisons and analysis of trends over time. Results: We treated 184 children, with 90% requiring admission. Comparing the first and second halves of the study, patients treated increased from 8.7 ± 4.8 (mean ± SD) to 24.5 ± 11.1 per year (P <. 01), patients requiring immediate operation increased from 4 (9%) of 44 to 24 (17%) of 140, and patients with serious injuries (resulting in direct intensive care unit admission, immediate operation, or death) rose from 12 (27%) of 44 to 51 (36%) of 140. Patient age was 11.5 ± 3.9 years. Sixty-eight percent of the children sustained multiple injuries and 50% required surgery. Only 35% of the children wore helmets. Conclusion: Over the 2 periods, there was a significant increase in number of patients treated, and considerable increases in serious injuries, and need for immediate operation. Despite inherent risks with riding ATVs, helmet use and patient age were remarkably low.