Borg Rating of Perceived Exertion Scale (RPE) is a psychophysiological measurements that translates physical stimuli to a psychological construct, which is perceived exertion. Its use is simple and it represents the effort perception. Each number of the scale is associated with a heart rate or percentage of maximal oxygen consumption (VO2max), which estimates the intensity of exercise.To validate RPE scale in patients with type 2 diabetes mellitus (DM2).Thirty five DM2 participants with a median age of 59 years underwent an incremental exercise test in a treadmill with breath-by-breath analysis of oxygen consumption. After every three minute stage, the RPE scale was applied and correlated with oxygen consumption variables.There was correlation coefficient of 0.91 between RPE score and VO2max. A RPE score of 11 corresponded to 52% of VO2max, a RPE score of 13 corresponded to 76% of VO2max, a RPE of 15 corresponded to 88% of VO2max and a RPE of 17 correspondent to a 100% of VO2max.RPE Scale is valid in patients with type 2 diabetes as an estimate of the intensity of physical activity.