Abstract: Background and Objective: The overall prognosis of patients with idiopathic brachial plexus neuritis was not satisfactory. The aim of this study was to report the short-term outcomes of early idiopathic brachial plexus neuritis after low dose corticosteroid combined with antiviral agent. Materials and Methods: Five patients with early brachial plexus neuritis from April-June, 2019 were included in this study. According to individual patient conditions, Electromyography (EMG), nerve B-ultrasound or brachial plexus Magnetic Resonance Imaging (MRI) were performed. After the diagnosis was confirmed, modified conservative treatments were initiated, including low dose corticosteroid therapy and antiviral therapy for 2 weeks and neurotrophic therapy for 4 weeks. Results: Of the 5 patients, only 2 patients had symptoms of pain at onset and 3 patients had sensory disturbances. Two patients had a common cold before onset. The lesion involved the upper trunk of the brachial plexus in 2 patients, MRI showed slightly intense signals, of which 1 patient also had supraclavicular lymph node augmentation. The other 3 patients suffered ipsilateral radial nerve palsy. At 1 month of modified treatment, 4 patients recovered well with almost complete shoulder and hand movements, however, their muscle strength was still weaker comparing with the contralateral side. One patient restored full ROM after surgery in 2 months. Conclusion: Early treatment is the key to good prognosis in patients with brachial plexus neuritis. Antiviral therapy combined with low-dose corticosteroid therapy may be superior to traditional treatment alone. In terms of early diagnosis, the clinical value of imaging examinations such as ultrasound and MRI was superior to that of EMG.