Abstract Background Hyperselective neurectomy (HSN) procedures in the spastic upper limb aim to reduce tone by excising some branches of the involved peripheral motor nerves at the point of entry of each motor ramus into the target muscle. Methods This prospective cohort study was conducted on 23 patients (12 males and 11 females aged from 14 to 68 years) who had upper limb spasticity at the Neurosurgery and Physical Medicine, Rheumatology, and Rehabilitation Departments of Tanta University hospitals. All studied patients had preoperative evaluation, neurological examination, and sonographic examinations with linear array transducers (frequencies ranging from 7.5 to 16 MHz). Results HSN was performed on the following: elbow flexors (16 patients), pronator teres (23 patients), wrist flexors (23 patients), finger flexors (23 patients), and thumb adductor (8 patients) for a total of 176 muscles over 23 surgical sessions, namely, a single session per patient. The first postoperative assessment was performed 6 months post-surgery, with the final assessment done at 12 months. Results showed an effective reduction of the spastic tone, spontaneous limb position, active and passive motion, and muscle strength ( p = 0.001). The results of HSN compare favorably with the other techniques of partial neurectomy; however, the technique requires detailed knowledge of upper limb motor anatomy. Conclusions The results of HSN technique in the management of the upper limb spasticity at our center have been promising, showing effective reduction of spasticity and improved motion, without any loss of strength.