PURPOSE: The purpose of this study was to assess social support, mood, and commitment to a plan for exercise of Korean adults with chronic diseases. Further, the relationships between social support, mood, and commitment to a plan for exercise were assessed. METHOD: The participants in this study were 230 Korean adults over 18 years of age with chronic diseases who were recruited in hospitals or health centers. The instruments used in this study were Exercise Social Support Scale, POMS (Profile of Mood States), and Commitment to a Plan for Exercise Scale. RESULT: The results of descriptive analysis showed that Korean adults with chronic diseases were perceived with relatively low commitment to a plan for exercise while they were perceived with moderate social support and mood states. Pearson's correlation coefficient showed significant relationship between these three variables. Stepwise regression indicated that 37% of the variance in commitment to a plan for exercise was explained by social support and vigor factor of the POMS. CONCLUSION: Health professionals can use this information for planning a targeted strategy to increase regular exercise among Korean adults with chronic diseases in order to improve their quality of life and control disease-related symptoms.