Purpose: The purpose of this study was to make a gender-based comparison of physical activity levels of older Korean adults with chronic diseases. Methods: Participants were 1,270 community-dwelling older adults (432 men; 838 women) who had chronic diseases and were over 65 years old. Data were obtained from the 2008 Korean Health and Nutrition Examination Survey. Data were separately examined for predictive factors of physical activity levels in older Korean men and women. The factors examined in the case of men were location of residence, basic livelihood, alcohol intake, and perceived health status and for women, location of residence, age, marital status, education, living arrangements, alcohol intake, suicide ideation, and perceived health status. Results: Data analysis showed that approximately 40% of older women with chronic diseases and 26% of older men were in the inactive group. Marital status (odds ratio [OR]=1.417, p=.003), alcohol intake (OR=0.617, p<.001), and perceived health status (OR=1.317, p<.001) significantly predicted physical activity levels for all older adults, irrespective of gender. Conclusion: These findings will help design gender-based interventions aimed at improving the health behavior of older adults.