Abstract- Introduction -Functional Capacity (FC) is a valid measure of physical fitness in health and disease and should be evaluated at the start and at the end of Cardiac rehabilitation programs (CRPs). However after comprehensive literature search we have not came across any of studies on diabetic patients comparing FC after inpatient rehabilitation. So this study was undertaken with the aim to compare the FC after inpatient CRPs in coronary artery bypass graft (CABG) surgery patients with and without diabetes using 6 minute walk test. Objective: Comparison of FC after inpatient CRPs in CABG patients with and without diabetes by performing 6 minute walk test (6MWT) using distance walked, % predicted distance and mean peak VO2. Methods and methodology: observational type of study conducted at tertiary care hospital, total of 32 subjects {Experimental group-16 in diabetes (DM) and Control group-16 in non-diabetes (non-DM)}. Stable CABG surgery patient were included. Exclusive criteria were graft taken from leg, lower leg amputation, unstable hemodynamic, Peripheral Vascular Diseases (PVD), BMI >30 kg/cm2 and Lower limb disability were excluded . FC using 6MWT was evaluated at the end of phase 1 CRP in both groups .6MWT was done using ATS guidelines.% predicted distance and mean peak VO2 calculated using equation. Result- The experimental group patients had statistically significantly less functional capacity as compared to the control group.