Work experiences among early adolescents are largely undocumented. Our purpose was to document the prevalence of work and work-related injury among lower-income Hispanic South Texas middle school students. Anonymous surveys were conducted in classrooms of sixth- through eighth-grade students, and 3,008 students reported current or recent employment. The prevalence of work was 56%; mean weekly work hours were 7.7. Increasing weekly work hours were significantly related to work injury (11-20 hours, odds ratio [OR], 1.5; 95% confidence interval [CI], 1.1-1.9; 21+ hours, OR, 2.4; 95% CI, 1.8-3.2, compared with 1-10 hours). The odds of injury were highest for agriculture (OR, 4.4; 95% CI, 3.3-6.0), followed by restaurant (OR, 3.8; 95% CI, 2.7-5.4), construction (OR, 3.6; 95% CI, 2.4-5.2), and yard work (OR, 1.7; 95% CI, 1.4-2.2). Working more than 20 hours weekly increased the likelihood of injury among middle school students. Parents and professionals should monitor weekly school-year work hours.