Background: Flexibility is regarded as a necessary component of normal biomechanical function. Tight hamstrings put an individual into risk of recurrent injury. The prevalence of hamstring tightness is very high in college going students among the age group of 18-25years. Hamstring tightness is not only a cause of limited range of motion, but it can also lead to a variety of other musculoskeletal issues. One of the most common complaints associated with hamstring tightness is hamstring strain. Objectives: To compare the effect of hand-held percussive massage versus instrument assisted soft tissue mobilization(IASTM) on hamstring muscle flexibility in young adults. Methods and Materials: The study was conducted on 100 subjects aged between 19-29 years of all genders, in which the subjects were divided in two groups namely, group-A and group-B which received treatment with hand-held percussive massage and IASTM respectively. The outcome measures i.e., Sit and reach test, active knee extension test and passive knee extension test were performed prior and post 1^st session and post 6 sessions of intervention. Results: This study resulted that both the groups showed improvement, but active knee extension was found to be significant in parameters of outcome measures in accordance with the group-B who received treatment with IASTM compared to another group. Conclusion: The present study concludes that the interventions given to group A and B using hand-held percussive massage and IASTM respectively, both were found equally effective. Whereas, group-B was more effective than group-A in term of active knee extension test and passive knee extension test.