Two patients with progressive, diffuse precancerous melanosis (intraepithelial atypical melanocytic hyperplasia or melanocytic dysplasia) of the conjunctiva were treated with cryotherapy. In one patient, the contiguous cutaneous portions of both eyelids were involved and received the same therapy; the extensive disease of the patient was managed by two cryotherapy sessions during a period of 21/2 months. The melanocytic process in both patients showed a good response to this therapy, which resulted in a slough of the superficial conjunctiva with reepithelialization from adjacent areas. Neither patients has shown recurrent disease in more than seven months of follow-up, although one patient had incomplete regression of the melanocytic condition in the perilimbal region, which was subsequently treated by an excisional biopsy. Serious complications occurred in one patient who had corneal and lenticular opacities; this patient had severe extensive disease for which exenteration was considered the only feasible alternative therapy to control the melanocytic proliferation disorder adequately. Less severe complications also developed, including trichiasis, ptosis, transient hypotony, and macular edema. In this article, we discuss the clinical and histologic features of acquired pigmentations of the conjunctiva, the criteria for their management, and the approaches to minimize the complications that we have encountered with cryotherapy.