The distribution of Langerhans cells (LC) in corneal and conjunctival epithelial flat mounts obtained from outbred albino Swiss-Webster mice of various ages was examined by histochemieal methods. The LC stain positively with ATPase and were negative to DOPA-oxidase. Mouse pup limbal conjunctival epithelium showed one or two LC/mm2. LC began to significantly increase in number by day 31 and ranged from 150-205/mm2in 7-48 week old mice. A slight decrease in LC was seen in 12 and 24 month old mice.