Equinus foot in spastic diplegic children is a major problem due to spasticity in gastrocnemius muscle that affects normal gait cycle, balance, and ADL. As per literature, though stretching is used as a technique for therapeutic management of spasticity, but current level of evidence to support the effectiveness of passive stretching in reducing spasticity in spastic CP children remains weak. AIM OF STUDY: To study effect of sustained static passive stretching on the reduction in spasticity of gastrocnemius, improving ankle dorsiflexion ROM, and improving GMFM in diplegic cerebral palsy by using a stretching device and conventional manual stretching. DESIGN: 30 subjects with mean age (4.94 ± 1.70) years of both male and female were taken in pre-post control experimental design and assigned randomly into two groups with 15 subjects in each group, viz. group-1 with mean age (4.85 ± 1.29) years treated by prolong static stretching given for 15minute using TS stretching device and group-2 with mean age (5.03 ± 2.08) years treated by manual stretching given for 1 minute. After 4 weeks of intervention data collection and data analysis was done. CONCLUSION: Prolong static stretching (15minute) has added benefits in decreasing in spasticity, gaining passive and active range of motion and improvement in GMFM as compared to conventional short duration stretching.