Objectives: Law enforcement is a high-stress and high-risk occupation that is one of the top ten sleep-deprived occupations. Most police officers who require to work night shifts, suffer from greater physical and psychological detrimental effects than other normal daytime workers. This study was intended to explore whether work stress is associated with the sleep quality of police officers. Methods: We used self-rated Pittsburgh Sleep Quality Index (PSQI) questionnaires to measure work stress and sleep quality among police officers working in southern Taiwan. Results: Police officers should pay more attention to their health and work stress. The analysis results showed that sleep quality among police officers was significantly poor, and work stress was significantly associated with sleep quality, police officers who had higher levels of work stress had the worst sleep quality, and such association was still significant under different demographic variables. Conclusion: The low sleep quality of police officers in southern Taiwan in this study was found to be associated with work stress. Those police officers often worked night shifts and showed poor health. We suggest that they should be provided with "good sleep awareness" education to improve their sleep quality and health.