The purposes of this study were to identify patterns of physical activity among white-collar men in Taiwan and to analyze the relationships between physical activity patterns and obesity indices. This cross-sectional survey included 350 subjects (between 21 and 75 years old). The Monitoring Trends and Determinants of Cardiovascular Disease Optional Study of Physical Activity Questionnaire (MOSPA-Q), developed and published by the World Health Organization (WHO) was used to measure subjects' daily energy expenditures attributed to physical activity. Obesity indices included body weight, body mass index (BMI), waist/hip ratio (WHR), body fat percentage, total cholesterol, triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL). Three patterns of physical activity, namely work-oriented, active, and light-active lifestyles, were identified through cluster analysis. The work-oriented group reported spending the most amount of time on work-related activities (10.5 hours/week). The active group spent the most time (1 hour/day) of the three groups on leisure activities. The light-active group spent the most time (7 hours/day) of the three groups on light activities. Referencing the 150 minutes/week of moderate- intensity physical activity recommended by the US Centers for Disease Control and prevention (CDC) for health gain as a cut-off point, 1.1%, 15.2%, and 29.1% of subjects in the active, light-active and work-oriented groups, respectively, failed to achieve this minimal level. Those in the work-oriented group categorized in high work-overload and prevalent inactivity situations returned the worst obesity indices (Body weight, BMI, WHR, and body fat percentages) adjusted by age.