AIM: To investigate the efficacy and safety of the treatment of endoscopic trans-ethmosphenoid optic canal decompression (ETOCD) with combination of steroid in patients with newly onset indirect traumatic optic neuropathy (ITON) and compare the outcome between immediate ETOCD treatment and ETOCD with preoperative steroid treatment. METHODS: Patients presented as newly onset ITON (suffered trauma within 3d) at a tertiary medical center between Mar 1st, 2016 and Mar 1st, 2018 were enrolled in this study. All patients were equally and randomly divided into 2 groups. Cases in group A were performed ETOCD immediately after admition while cases in group B were prescribed by methylprednisolone (20 mg/kg · d) for 3d before ETOCD. Methylprednisolone (20 mg/kg · d) was used after surgery for 6d in group A and 3d in group B. Follow-up was up to 3mo in all cases. Visual acuity (VA) before and after treatment between the two groups were taken into comparison. RESULTS: Complete postoperative data were acquired from 34 patients in group A and from 32 patients in group B. Group A had significantly higher effective rate in VA than group B (χ2 =4.905, P=0.027). CONCLUSION: For patients with newly onset ITON, combination treatment of ETOCD with high-dose steroid is an effective and safe way. Immediate surgery will lead to better prognosis for these cases.