For the past 3 decades, police officers have been diagnosed with various stress-induced health problems. Police officers are at a greater risk of various environmental health problems due to the stressful nature of their profession. While there is abundant research that explores the relationship between high stress occupations and environmental health, researchers have yet to sufficiently explore the relationships between police officers' job stress and job performance. The purpose of this correlational study was to use Cohen & McKay's conceptualization of the stress-buffering hypothesis to explore whether police officers' physical exercise moderated the negative impact of job stress on their job performance. Data were collected through an online survey administered to police officers from 2 metropolitan police departments in the United States, and data were analyzed using a hierarchical regression procedure. Findings indicted that approximately 80% of the variance in police officers' job performance is explained by job stress, indicating a negative relationship between police officers' job stress and job performance. The findings also indicated that police officers' physical exercise was positively related to their job performance. Positive social change implications stemming from study may include recommendations to police department leadership to emphasize the importance of moderating occupational stress through exercise as a method to improve their job performance. These efforts may contribute to improved public safety outcomes in communities in the United States.