Purpose: This study aimed to investigate the functional outcomes of infants who underwent neurotization for shoulder abduction and elbow flexion in Narakas grade 1 birth-related brachial plexus palsy (BRBPP) and compare this cohort to children who progressed past the point of needing intervention. Methods: A cohort study was conducted at a single center between 1999 and 2010. Two-hundred and eight infants were identified with BRBPP that presented for neurosurgical care as infants. Of those, 38 (18 %) received neurosurgical intervention with approximate 2-year follow-up. Only infants undergoing cranial nerve XI to suprascapular nerve neurotization for shoulder abduction (SA) weakness and medial pectoral nerve to musculocutaneous nerve neurotization for elbow flexion (EF) weakness were included. In addition, 30 infants who improved past the need for surgical intervention and had been followed for close to 24 months were identified for comparison. Descriptive statistics and exploratory analysis were performed using SAS 9.2 and JMP 9.0.2. Results: Shoulder abduction For SA, there were no differences in age at presentation between the operative (6–9 months) and non-operative (5–9 months) groups (p = 0.99). Infants in the operative cohort had significantly worse initial function (p = 0.008). At 2-year follow-up, the two groups had become similar (p = 1.0). Elbow flexion For EF, there were no differences in age at presentation between the operative (6–8 months) and non-operative (5–8.5 months) groups (p = 0.98). Infants in the operative cohort had significantly worse initial function (p = 0.002). At 2-year follow-up, those two groups had become similar (p = 0.26). Conclusions: Infants undergoing neurotization for Narakas grade 1 brachial plexus injury had similar long-term function to those who had improved and never required surgery. The preoperative exam findings were significantly different between the intervened and non-intervened groups, while the postoperative exam findings were not.