The purpose of this study was to investigate the influence of relative factors on regular physical activity among Taipei City police officers. A total of 396 police officers at the Taipei City Police Department were selected using a stratified random sampling method. Information about demographic characteristics; worksite environment; socio-psychological factors; and the type, duration, frequency, and intensity of physical activity was collected through a self-administered questionnaire. The data were analyzed by descriptive statistics, a chi-square test, analysis of variance, correlation, logistic regression, and multiple regression. The results showed that only 21.3% of the police officers performed physical activity regularly. Work shifts and perceived exercise barriers were predictors of regular physical activity. Self-efficacy, perceived health status, perceived exercise barriers, and benefits were predictors of the level of physical activity. Regular physical activity is low among Taipei City police. It is recommended that work shifts and socio-psychological factors be taken into consideration when developing a physical activity-based health promotion program.