Objective: To determine the gender based differences in quality of life after phase II cardiac rehabilitation in post coronary artery bypass graft surgery (CABG) Material & Methods: A Quasi experimental study was conducted Shifa international hospital (SIH) Islamabad from June 2017 to November 2017 (IRB&: 778-053-2017). The sample of n=30 participants (male = 15, female = 15), were collected through non-probability Convenient sampling method. Male and female participants between 45-60 years of age with coronary artery bypass graft surgery and completed phase I cardiac rehabilitation program were included in the study. To measure quality of life RAND 36-Item Health Survey was used at 0 week and after 8 week. Results: The mean age of study participants in female was 54.53±3.357 and male 55.60±5.20 years. The results showed that there post intervention significant improvement was observed in male than female regarding physical functioning (33.33±4.98 vs. 70±41.40, p=0.028). Role limitation due to physical health also showed more improvement in male than female (MD=21.66). Role limitation due to emotional showed significant improve in females than male (26.66±45.77 vs. 80±41.40, p=0.002). Conclusion: The study indicated that 8 week phase II cardiac rehabilitation programs had significant role in improving all domains of Quality of life (SF-36). But physical function, role limitation due to physical health and role limitation due to emotional problem were more improved in male as compare to female. Keywords: Cardiac rehabilitation, CABG, quality of life, gender