Background and Aim: In today sports such as volleyball and basketball, Vertical Jump is considered as important component that enhance the performance of athlete. The aim of this study was to determine the effect of muscle energy technique on vertical jump performance in volleyball and basketball players. Methodology: This Randomized Clinical Trial was conducted at Islamic International University Islamabad. Twenty-nine athletes of age 18 – 35 playing basketball and volley as part time/domestic level were included. Post isometric relaxation technique was applied on group A (n=15) and static stretching was applied on group B (n=14). Surface electromyography activity of quadriceps and abdominal muscle was recorded, Stable time, airtime and vertical jump height were measured using two-axis force platform and vertical jump height was measured by motion sensor. Measurements were taken at baseline and immediately after applying interventions to both groups. Data entry and analysis were done by using software SPSS version 22. Results: Of the 29 athletes, 15 were in the group A and 14 were in the group B. Immediate assessment of vertical jump height was not significantly improved by post-isometric relaxation relative to static stretching (p=0.594). Muscle recruitment, ground reaction and vertical jump height improved apparently after post isometric relaxation but not significantly. Conclusion: It appears that post isometric relaxation and static stretching of quadriceps shows no significant difference in vertical jump height.