Purpose: To evaluate the clinical feasibility and effect of neuromuscular electrical stimulation (NMES) therapy of quadriceps femoris (QF) and tibialis anterior (TA) muscles on improving gait and functional outcomes in children with spastic cerebral palsy (CP). Method: Ten children with spastic diplegic/hemiplegic CP who were in the age group of 7 to 14 years recruited from a rehabilitation institute were randomly assigned either to a control group or a NMES group. Both groups obtained conventional physiotherapy and muscle strengthening exercises. The NMES group in addition received surface electrical stimulation to QF and TA muscles for four weeks duration. Results: The NMES group showed significant improvements as compared to the control group in walking speed (mean difference: 7.83 meters per min, 95% confidence interval: 3.13 to 12.53, p<0.01) and cadence (mean difference: 23.33 steps per min, 95% confidence interval: 5.90 to 40.77, p<0.01). The NMES group also showed significant reduction in physiological cost index of walking or PCI (mean difference: −1.32 beats per meter, 95% confidence interval: −1.83 to −0.80, p<0.001) indicating greater energy-efficiency of walking. No significant changes were seen in EMG parameters. Conclusions: The findings of this study suggests that NMES therapy together with conventional physiotherapy more efficiently improves walking ability and functional outcomes as compared to conventional physiotherapy alone in children with spastic CP.