Purpose: This study was done to compare social support, depression and quality of life (QoL) in adult (under 65) and elderly (over 65) patients who had coronary artery bypass surgery. Methods: Participants were 66 adult and 68 elderly patients who completed questionnaires on social support, depression and QoL. Data were collected from December, 2011 to January 2012 and analyzed using x2 -test, t-test, and Pearson's correlation. Results: The adults’ physical QoL scores were significantly higher than those of the elders (t=2.58, p=.011). However, the average difference between physical and mental QoL based on age, after controlling for gender, showed that there was no significant difference in QoL between adults and elders. In adults, significant negative correlations were found between depression and social support (r=-.41, p<.001), physical QoL (r=-.48, p<.001), and mental QoL (r=-.56, p<.001), and significant positive correlation between social support and mental QoL (r=.25, p=.047). In elders, significant negative correlations were found between depression and social support (r=-.43, p<.001), physical QoL (r=-.45, p<.001), and mental QoL (r=-.56, p<.001), and significant positive correlation between social support and mental QoL (r=.28, p=.019). Conclusion: Age-differentiated nursing intervention programs should be developed, and studies should be conducted to verify effectiveness of programs.