Injury from personal watercraft has continued to increase. Prior attempts to delineate patterns of injury and relative frequencies have yielded varied results. We retrospectively reviewed Trauma Registry data and charts of all patients who suffered personal watercraft injury treated at the R. Adams Cowley Shock Trauma Center between August 1996 and January 2001. Patient demographics included mechanism of injury, injuries sustained, and outcomes. Attempts were made to correlate events around the injury and injury pattern. During the study period 24 patients were treated. Mechanisms consisted of direct collision, fails from the watercraft, handlebar straddle injuries, axial loading, and hydrostatic jet injury. Traumatic brain injury was most common occurring in 54 per cent of patients. Spinal injury was also common occurring in 29 per cent of patients. Axial loading from falls while wave jumping seemed to correlate with skeletal injury. Thoracolumbar spine injury were often skeletally unstable requiring either brace or operative fixation. Inexperience and reckless behavior were found to be the greatest contributing factors. Substance abuse did not influence injury.