Introduction:It is diffi cult to measure energy expenditure and oxygen consumption in elderly on a daily clinical basis due to expensive & cumbersome equipments required to measure it. Physiological cost index is relatively easy to perform, safe and cost eff ective and uses a mode of exercise that is integral to their activities of daily living.Aim: To fi nd the physiological cost index (PCI) of 6 minute walk test and its correlation with 6 minute walk distance in elderly.Study Design: Its a correlational study conducted on 60 individuals above 60 years of age during a period of one year.Study Procedure: The 6 minute walk test was conducted along a long 30m hallway. The distance walked and heart rate, respiratory rate, blood pressure and rate of perceived exertion were recorded pre and post test. Using the data obtained from 6 minute walk test, PCI was calculated.Statistical Analysis : Pearson's rank order correlation coeffi cient test and t-test was used to analyse the data. Results:The mean PCI is 0.17±0.12 beats/m in elderly in our study. The mean 6 minute walk distance is 282.07±63.14 m. There exists a correlation between physiological cost index and 6 minute walk distance in elderly individuals which is statistically signifi cant. Conclusion:Physiological Cost Index is decreased in elderly. There exists a correlation between physiological cost index and 6 minute walk distance in elderly.