Dr. Charles Jennissen, of the University of Iowa Department of Emergency Medicine presented this at CPSC's ATV Safety Summit Oct. 12, 2012. The study objective was to understand the effect of passengers on ATV-related crashes and injuries. Methods: A retrospective chart review was performed of ATV-related injuries from 2002-2009 at a university hospital. Results: 345 cases were identified of which 20% were passengers or drivers with passengers. Females and children were more likely to be passengers. Overall helmet use was low (~20%), and passengers were less likely than operators to wear helmets. There was a trend observed wherein passengers increased the likelihood of rollovers on sloped terrains, with backward rollovers the most likely to involve passengers. Victims who fell/were ejected to the rear were significantly more likely to have been on an ATV with passengers than were victims of other ejections or those not ejected, and also had more severe head injuries. Self-ejections and forward ejections appeared less likely with passengers. Patients who self-ejected had higher extremity injury scores than patients who fell/were ejected by other mechanisms, but had less severe head injuries. Conclusions: Passengers on ATVs may be at greater risk for fall/ejection to the rear and rearward falls/ejections appeared to increase the risk of head injury. Strict and well enforced "no passenger" laws could reduce risk of some ATV crashes and injuries.