The purpose of this study was to report the resolution of persistent Sub-Retinal Fluid (SRF) induced by subthreshold micropulse laser treatment in a patient, formerly treated for rhegmatogenous retinal detachment by retinal pneumopexy. The case was a 41-year-old male, who initially presented macula-splitting rhegmatogenous retinal detachment and corrected distance visual acuity of 20/40 in his left eye. He was treated by retinal pneumopexy and laser retinopexy. Retina was flattened and vision improved to 20/30. However, the subretinal fluid (SRF) under the fovea was persistently observed on repeated retinal exams. Fourteen months after the initial pneumopexy, subthreshold micropulse laser was applied to cover the entire area of the SRF. The improvement started two weeks afterwards and the SRF completely resolved within four months after the application of micropulse laser. Corrected distance visual acuity improved from 20/30 to 20/20, accompanied by marked improvement in patient's complaints on visual blurriness. The patient was followed up for three years and no recurrence of SRF was noted. The findings of this report indicate that subthreshold micropulse laser may serve as a therapeutic option for persistent SRF, which may be observed after successful retinal detachment repair.