Closure of the peripheral iridectomy (PI) may lead to forward displacement of silicone oil (SO) in some but not all SO-filled aphakic eyes. In this study, we report three patients with a history of a combined three-port pars plana vitrectomy and cataract surgery, SO injection and inferior PI who underwent laser retinopexy a few months postoperatively. The postoperative courses of these patients were unremarkable except for the closure of the PI without anterior displacement of SO; however, a few hours after laser therapy the SO was displaced to the anterior chamber, leading to acute glaucoma in one of the cases. Yttrium aluminium garnet (YAG) laser was successfully used to reopen the PI in all three patients. The induction of a pupillary block following laser retinopexy in SO-filled aphakic eyes with a closed PI and no forward displacement of SO underscores the necessity of a follow-up examination after laser therapy in such patients and the importance of the prophylactic use of a YAG laser to reopen the PI before laser therapy.