The purpose of this study was to test seven constructs (prior experience of exercise, perceived health status, exercise benefits, exercise barriers, exercise self-efficacy, social support for exercise, and options for exercise) from the health promotion model (HPM) as a causal model of commitment to a plan for exercise in a sample of 400 Korean adults with chronic disease. Using structural equation modeling (SEM), we found that all fit indices indicated a good fit. The final model accounted for 54% of the variance in commitment to a plan for exercise. Prior experience with exercise and exercise benefits were the factors most highly related. Health professionals can assess prior experience and emphasize personally relevant benefits of exercise in designing intervention programs to help Korean adults with chronic disease become more physically active.