Four cases of fungal corneoscleritis complicating beta-irradiation-induced scleral necrosis after pterygium excision have presented to our institution in recent years. Two cases were due to Petriellidium boydii and one each to Fusarium and Scedosporium inflatum. The condition may remain undiagnosed for weeks to months and becomes chronic with perforation or incipient perforation. The infections may masquerade as a chronic red eye, posterior scleritis or serous retinal detachment. Penetrating or lamellar keratoplasty is required following debridement of necrotic tissue. Prolonged systemic antifungal therapy may still fail to eradicate infection. Visual outcome is usually poor, and one of our patients required enucleation. Removal of calcific plaques from ulcer beds should be accompanied by disinfection, debridement and culture, since these beds and plaques are frequently a nidus of infection. Subsequently these ulcers may be covered with lamellar grafts or conjunctiva. We would caution against the use of radiotherapy to prevent recurrence of pterygia.