The thirty second chair stand test has been used as a measure of lower body fitness in older adults from 60 – 90 years, healthy or unhealthy. This study aims at establishing the reliability and validity of this technique as a measure of lower body strength in an Indian population in individuals of age groups 20 to 59 years. OBJECTIVES: To evaluate the thirty second chair stand test (CST) as a measure of lower body strength in an Indian population. METHODOLOGY: A prospective case study was done from June 2017 to June 2018 in the department of Physical medicine and rehabilitation in 100 subjects of the ages of 20 to 59 years. For the 30 – second CST, individuals were required to stand up from a standard chair to a fully extended standing position as many times as possible with their arms folded across their chest. The number of completed repetitions achieved in 30 seconds was recorded. Test retest reliability was evaluated by performing this test on two separate occasions 1 week apart. Intra – class variations was analyzed across age and gender. FINDINGS: Intraclass reliability R ranged from 0.98 to 0.99 – with a majority of values being 0.99 indicating that the tests have good relative reliability across trials. ANOVA results revealed no significant changes from scores from day 1 testing to day 2 retesting, thus indicating that the tests also have absolute reliability across trials. The scores were found to decline across age and are lower for older age group (40 – 59) as compared to younger (20–39). The scores were found to be lower for females as compared to males. CONCLUSIONS: The results of this study indicate that the THIRTY SECOND CHAIR STAND TEST is a reliable test to measure lower body strength. We assessed construct validity across age and gender and a positive trend was found. Hence it is a valid test.