Selective Dorsal Rhizotomy (SDR) is a neurosurgical procedure currently used as a surgical treatment of children with spasticity in their legs. In SDR, the dorsal roots from L2 to S1 or S2 is partially sectioned. The primary goal of SDR is to reduce spasticity and improve the range of movement with preservation of muscle strength. The dorsal roots involved in spasticity are identified on the basis of intraoperative electrophysiological stimulation. Currently, SDR is most commonly performed for the treatment of spastic cerebral palsy in children. We report an 8-year-old child with spastic cerebral palsy who underwent intraoperative neurophysiology monitoring during SDR for treating his spasticity. Before the operation, patient’s examination revealed more spasticity at the lower extremities, mild spasticity at the upper extremities, and occurrence of fixed contracture of his both ankle joints. Intraoperative neuromonitoring (consisting of motor evoked als, direct nerve root stimulation, and free run electromyography) was performed during the operation. Electrophysiological monitoring was initially used to help differentiate between the ventral and dorsal roots and cutting the abnormal sensory rootlets. After the operation, his motor power of the lower extremities in the proximal and distal muscles was 4 out of 5, his saddle sensation became normal, and there was no urinary and stool incontinency. Four weeks after the surgery, he could walk about 10 m without help. His examination at 2 and 4 weeks after the operation showed was no sign of sensory deficits, urinary, or stool incontinency. Two months after the operation, the patient could walk independently without help while before the operation, he could not.