An 85-year-old male with glaucoma presented with a 1-1/2 year history of tearing; red eyes; and pruritic, edematous, eczematous eyelids. Treatment for presumed ocular rosacea and seborrhea was unhelpful. Patch testing to our standard 64 antigens yielded a positive reaction to Balsam of Peru. Notably, benzalkonium chloride, thimerosal, and other preservatives elicited negative reactions. Repeat open application testing elicited positive results to Xalatan (latanoprost) 0.005% ophthalmic solution (Pharmacia & Upjohn, Kalamazoo, MI). A second session of patch tests to 10 personal products, in addition to Xalatan 0.005% solution and the Xalatan vehicle (provided by the manufacturer), elicited a strong positive reaction only to the full preparation of Xalatan 0.005% solution. This report describes the first known case of ACD to latanoprost, a new prostaglandin analog that is widely prescribed for treatment of glaucoma.