Quatman, CE, Myer, GD, Khoury, J, Wall, EJ, and Hewett, TE. Sex differences in "weightlifting" injuries presenting to united states emergency rooms. J Strength Cond Res 23(7): 20612067, 2009-Benefits of resistance training include improved muscle strength and sports performance and may include reduced injuries. However, few studies have examined sex differences in resistance training-related injuries. The objective of this investigation was to evaluate sex differences in injuries associated with strength training in adolescents and young adults by type (sprains and strains, fractures), mechanism (accidental, nonaccidental), and location (head, trunk, arm, hand, leg, foot) of injury. We hypothesized that there would be sex differences in type, mechanism, and location of strength training injuries. The U. S. Consumer Product Safety Commission (CPSC) National Electronic Injury Surveillance System (NEISS) was queried from 2002 to 2005 using the CPSC code for "Weightlifting." Subjects between the ages of 14 and 30 years were included in the study. CPSC sampling weights were used to calculate national estimates from the sample of 3,713 patients (men = 3,102; women = 611). Weighted Chi-square analyses were used to compare differences in mechanism, type, and location of injury for men versus women. Men had significantly more sprains and strains (p = 0.004), whereas women demonstrated increased accidental injuries compared to men (p < 0.001). The trunk was the most commonly injured body part for both men (36.9%) and women (27.4%). Men had more trunk injuries than women (p < 0.001), whereas women had more foot (p < 0.001) and leg (p = 0.03) injuries than men (p < 0.001). The findings indicate that men may suffer more exertional-type resistance injuries during strength training (sprains and strains) compared to women, especially at the trunk. Conversely, women may be more susceptible to lower-extremity injuries resulting from accidents during resistance training.