Pterygia, triangular sheets of fibrovascular tissue that invade the cornea, have recurrence rates of 30% to 50% with currently available surgical procedures. 2. Mitomycin, an antimetabolite-antibiotic agent, has been reported to be effective in preventing recurrences of surgically excised pterygia when used adjunctively as eye drops. 3. Because mitomycin-C is an antineoplastic agent, appropriate policies and proper patient education are important.