AIM: To assess surgical outcomes of a novel method of transscleral drainage of subretinal fluid using a 25-gauge trocar-cannula with a self-closing valve (DTV) in patients with severe exudative retinal detachment (ERD) in Coats disease. METHODS: Retrospective consecutive cases of 20 patients (20 eyes) of severe ERD due to Coats disease (stage 3B) in total 156 Coats patients between June 2015 and April 2019 were included in this study. The participants were aged 1 to 10y with a mean age of 3.50 +/- 1.79y. The mean follow-up time were 11.9mo. Subretinal fluid was drained transsclerally using a novel method of DTV. The height of the retinal detachment and the regression of abnormal vessels including telangiectasias and aneurysms were observed. Complications including vitreoretinal fibrosis, tractional retinal detachments (TRD), endophthalmitis, retinal holes, and hemorrhages were evaluated. RESULTS: Following surgeries, the patients showed the replacement of ERD and regression of telangiectatic retinal vessels observed with binocular indirect ophthalmoscopy. Six patients received retinal cryotherapies and 12 patients received laser photocoagulations following first external subretinal fluid drainage using DTV. All patients underwent intravitreal anti-vascular endothelial growth factor therapies to induce residual subretinal fluid absorption. During followups, 8 patients underwent a second drainage operation, 17 patients received retinal laser photocoagulations and 7 patients received cryotherapies. Vitreoretinal fibrosis was found in 7 patients and 6 patients underwent micro- invasive vitrectomies during the follow-up period. Severe TRD, iatrogenic retinal holes, and hemorrhages were not found. CONCLUSION: The authors present a new therapeutic approach that successfully drains subretinal fluid in advanced stage 3B Coats disease with severe ERD. This is a simple, safe and less invasive approach when compared with traditional managements. However, it should be strictly selected for patients with high bullous ERD close to the central axis of the eye in order to avoid the complication of retinal holes.