Aim of this study was to assess the reliability and validity of RT6 in healthy, young, sedentary adults. A total of 41 healthy, young, sedentary adults were recruited to this study. Sociodemographic data and IPAQ were collected from the subjects. Subjects wore RT6 accelerometer and pedometer on their pelvises. Subjects were asked walk at their normal and brisk walking speeds for 10 minutes. These activities were repeated on a treadmill using the individual speeds from normal ground walking on two settings 1 week apart. Bland-Altman analyses were performed to determine the mean difference and the levels of agreement. The Cronbach's alpha coefficient of the questionnaire was used. There was a 63.2% agreement between the treadmill and the normal ground at normal speed measurements. There was no statistically significant correlation between the pedometer and other measures. This study found that RT6 is a valid measurement tool at normal and active walking speeds in measurement of physical activity.