From 1980 to 1990, 32 consecutive patients with progressive cystic or diffuse epithelial ingrowth of the anterior chamber were treated successfully with block excision. This technique consists of simultaneous removal of adjacent iris, pars plicata of ciliary body, and all layers of sclera and cornea in contact with the lesion acting as a shell. The resulting defect is covered by a tectonic corneoscleral graft. Twelve patients had suffered from perforating ocular injury, 10 patients had previously undergone cataract extraction, and 10 patients had various causes of epithelial ingrowth. Cystic epithelial ingrowth occurred in 27 patients, diffuse sheetlike epithelial ingrowth occurred in four patients, and one lesion was identified as foreign body granuloma. On histopathologic examination, all but two patients revealed epithelial involvement of the surface of the ciliary body. All patients were followed up for an average of 60.1 months (range, 1 to 120 months). Long-term visual acuity was better than 20/60 in 37.5% of the patients. No recurrence of ingrowth was noted and enucleation was not necessary. Our results indicate that block excision currently may be the treatment of choice for cystic and diffuse sheetlike epithelial ingrowth of the anterior chamber.