The purpose of this study was to compare the epidemiology of freestyle and Greco-Roman wrestling injuries sustained during a 2006 United States (US) national tournament. A prospective injury surveillance study was conducted at the US 2006 ASICS/Vaughan Cadet and Junior National Championships. There were 83 freestyle- and 55 Greco-Roman-related injuries sustained, with the rate of injury per 1000 athlete-matches higher in freestyle (7.0) compared with Greco-Roman (4.6) wrestling [Rate ratio (RR)=1.51, 95% confidence interval (CI): 1.07-2.12]. Compared with Greco-Roman wrestling, there was a greater proportion of knee injuries in freestyle wrestling [injury proportion ratio (IPR)=4.17, 95% CI: 1.30-13.41]. In GrecoRoman wrestling, there were greater proportions of elbow (IPR=9.11, 95% CI: 1.13-73.59) and head/face/neck (IPR=1.72, 95% CI: 1.10-2.67) injuries and a greater proportion of concussions (IPR=1.95, 95% CI: 0.92-4.12), although the latter was statistically insignificant. Greco-Roman wrestlers sustained a greater proportion of injuries from being driven into the mat (IPR=2.97, 95% CI: 1.72-5.14). There were no statistically significant differences in injury outcome by wrestling style. The differing injury rates and patterns of injury between freestyle and Greco-Roman wrestling are likely due to the different rules between these styles that allow lower leg attacks in freestyle wrestling and encourage the use of throws in Greco-Roman wrestling.