Abstract Introduction Shiftwork is inevitable in law enforcement. Officers are scheduled around-the-clock to protect and serve communities. Many police departments are also understaffed; consequentially, officers’ work schedules often include long work hours. Shift work and long work hours can result in sleep loss, poor sleep quality, and fatigue. In turn, these factors can impair police officers’ operational performance. We investigated whether sleep loss and poor sleep quality increase odds of on-duty injuries or disciplinary actions in policing. Methods Officers (n=113) that started their careers as police officers at the Buffalo Police Department between 1994–2001 were studied. Work and injury data were obtained for each officer starting with their hire date and continuing day-by-day for 15-years. Between 2004–2009, officers reported any disciplinary actions in the prior two years and their sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and Survey Screen for Apnea. Data were analyzed using logistic regression with logit link functions (PROC GLIMMIX, SAS 9.4). Covariates included sex, ethnicity, experience, shift type, workload, and secondary employment. Results Seventy-four percent of officers had poor sleep quality (PSQI global score ≥ 5). Officers with poorer sleep quality had greater odds of injury (OR=1.3 [95% CI: 1.0–1.5], p=0.03). Officers’ sleep duration was not a significant predictor of injuries (OR=1.0 [95% CI: 0.3–3.2], p=0.96). Officers with sleep disturbances (OR=3.5 [95% CI: 1.0–11.8], p<0.05) and/or using sleep medications (OR=15.7 [95% CI: 2.8–89.3], p<0.01) had higher odds of injury. None of the variables were significant predictors of disciplinary actions. Conclusion Poor sleep quality was prevalent among the officers. The natures of the injuries were likely multi-factorial and complex. Notwithstanding, poor sleep quality was associated with higher odds of on-duty injuries. The source of officers’ sleep disturbances (e.g. shift work, insomnia, and/or policing-related stresses) remains to be determined. Support CDC/NIOSH grant 1R01OH009640-01A1; NIJ grant 2005-FS-BX-0004