All-terrain vehicles (ATVs) have increased in popularity and sales since 1971. This rise in popularity led to an increase in injuries resulting in voluntary industry rider safety regulations in 1988, which expired without renewal in 1998. Our purpose was twofold, to determine the incidence and severity of ATV injuries in our patient population and what, if any impact the safety regulations had. To further characterize the risk of ATV use, we compared them to a vehicle generally recognized as dangerous, the motorcycle (MC). Our trauma registry was reviewed from January 1998 through August 2004 for ATV or MC injured. Data collected included age, gender, mortality, Injury Severity Score (ISS), helmet use, and injury distribution. These were compared to our data from the decade of regulation. There were 352 MC and 221 ATV patients. ATV injured demonstrated a higher proportion of pediatric and female patients (P < 0.001 and P < 0.01, respectively), a decrease in helmet use (8.6% vs 64.7%, P < 0.001), and increased closed head injuries (CHI) (54.2% vs 44.9%, P < 0.05) compared with MC injured. ISS and mortality were similar. The average number of patients from 1988 to 1998 was 6.9/yr compared to 31.6/yr (P < 0.001) during 1998-2004 with equal ISS. Our data show that there has been a dramatic and progressive increase in the number of ATV crashes since expiration of industry regulations. ATVs are as dangerous as MCs based on patient ISS and mortality. There are significantly more children and women injured on ATVs. The lower rate of helmet use in ATVs may account for the significantly greater incidence of CHI. These data mandate the need for injury prevention efforts for ATV riders, in particular children, through increased public awareness and new legislation.