The development of a full-thickness macular hole (FTMH) after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) repair is a rare occurrence. We report the first case of rapid MH formation with internal limiting membrane (ILM)-like hyper-reflective bridging membrane under silicone oil (SO) meniscus, noted on the first postoperative day (POD) postvitrectomy for RRD. A 57-year-old man presented with best-corrected visual acuity (BCVA) of perception of light with immature cataract and total RRD in the left eye. He underwent cataract extraction with intraocular lens implantation with uneventful PPV, endolaser to primary break, and 360° periphery followed by injection of 1000 Cst SO. On the first POD, retina was attached in all quadrants with SO in situ. However, a dark red spot was noted at macula which was confirmed as FTMH with a bridging linear hyper-reflectivity under SO meniscus on optical coherence tomography (OCT). Repeat OCT, at 2 weeks and 3 months, revealed closed MH under the SO meniscus with BCVA improving to 6/60. This is the first reported case of very rapid FTMH formation with an ILM-like linear hyper-reflectivity following vitrectomy for RRD and highlights the possible contributory role of multiple nonconventional factors for rapid FTMH development and fibrinous membrane-assisted closure under SO tamponade.