A 66-year-old man developed an unexplained corneal decompensation 7 years after extracapsular cataract extraction and implantation of a single-piece poly(methyl methacrylate) (PMMA) posterior chamber intraocular lens (IOL). He had penetrating keratoplasty (PKP). Two years later, he developed corneal graft failure secondary to an IOL haptic fragment in the anterior chamber angle. The patient had a repeat corneal graft and IOL exchange. The broken haptic was examined with scanning electron microscopy. The findings were consistent with late fracture of the haptic within the capsular bag, which was presumably weakened by an improper implantation technique. Fracture of a PMMA haptic should be suspected as a cause of corneal decompensation and corneal graft failure after cataract surgery. This case emphasizes the importance of safe implantation techniques.