Background: Patients following Coronary Artery Bypass Graft (CABG) may experience a decrease in their functional capacity and productivity due to a decline in cardiac output. Walking exercise is considered an easy aerobic activity that may enhance the heart’s pumping ability, leading to improvements in patients' functional capacity and productivity.Purpose: This study aimed to assess the effect of walking exercise on functional capacity and productivity in patients after CABG.Methods: This study used a Randomized Controlled Trial (RCT) design with a single-blind outcome assessor. A total of 42 respondents participated, divided equally into intervention and control groups (21 each).Results: The study showed a significant effect of walking exercise on functional capacity (p= 0.008), impairment while working (p= 0.011), and activity impairment (p= 0.044). However, there was no significant difference in work time missed (p= 0.967) or overall work impairment (p= 0.696) between groups.Conclusion: Walking exercise improves cardiac function and metabolism, increasing Adenosine Triphosphate (ATP) expenditure, thereby enhancing functional capacity and productivity in patients.