Intraoperative massive suprachoroidal hemorrhage during pars plana vitrectomy. Seven eyes (7 patients) developed massive suprachoroidal hemorrhage (MSCH) during pars plana vitrectomy (PPV) for complicated retinal detachments. The MSCH developed late in the procedure following PPV, air fluid exchange, endolaser, cryopexy, and scleral buckling in five of seven eyes. In two eyes, mild hemorrhagic choroidal detachments noted intraoperatively progressed to MSCH within 72 hours postoperatively. Diagnosis of MSCH was confirmed by echography and CT scan. Multiple scleral buckling surgeries, high myopia, aphakia, and intraocular inflammation were the main risk factors. Placement of a broad posterior scleral buckle with intraoperative hypotony and cryopexy were important precipitating factors. Visual results were poor, with six of seven eyes showing no light perception. The mean follow-up time was 12.8 months. Once acute MSCH is recognized intraoperatively, surgical decompression at that time should be avoided as MSCH itself may tamponade the choroidal bleed. Details of prevention and management are discussed. 