Few epidemiologic studies have evaluated sex differences in work-related injury rates. In this study, the authors examined injury trends by type of injury, severity of injury, and how the injury occurred among a cohort of 9,582 female and 26,898 male electric utility workers employed during 1980-1992 by the Southern California Edison Company. Sex-specific unadjusted injury rates were higher throughout the period for male workers. However, after adjustment for occupation, job experience, and age, elevated rate ratios indicate that female workers have higher injury rates. Mantel-Haenszel summary rate ratios and 95% confidence intervals were 1.49 (1.43-1.54) for all types of injuries, 1.27 (1.16-1.39) for head and neck injuries, 1.48 (1.38-1.58) for upper extremity injuries, 1.11 (1.01-1.21) for back injuries, and 2.11 (1.97-2.25) for lower extremity injuries. The rate ratios were slightly higher for more severe injuries, which suggests that potential reporting bias was not a likely explanation for these findings. The authors conclude that differences between male and female workers in training, physical capacity, task assignments, and other factors could explain these injury trends.