The present study aimed to examine the effects of playing Nintendo Wii games on upper extremity functions compared with conventional physiotherapy, in children with obstetric brachial plexus injury (OBPI). Twenty-two patients with brachial plexus injuries were enrolled. The patients were divided into two groups by simple randomization. The control group (conventional physiotherapy group [CTG]: n = 11) received conventional physiotherapy for 6 weeks (40minutes per day, for 4 days per week). The study group, called Nintendo Wii group (NWG; n = 11), received conventional physiotherapy as well as tennis, baseball, and boxing games with Nintendo Wii on days when there was no physical therapy. The upper extremity range of motion (ROM) was evaluated using a digital goniometer, motor function was assessed using the Active Movement Scale (AMS), and shoulder functions were assessed with the Mallet Scoring System MSS). Virtual reality treatment had a positive effect on shoulder flexion, forearm pronation, wrist flexion, ROM, and functionality (p< 0.05). There was a significant improvement in shoulder abduction and shoulder external rotation in the CTG (p< 0.05). There was no significant difference in the MSS values of either groups (p> 0.05). As per the AMS, in the NWG, the shoulder internal rotation increased significantly (p< 0.05). Nintendo Wii treatment used in addition to conventional physiotherapy may be effective in increasing upper extremity functions in children with OBPI.