BACKGROUND Dermatitis of and around the eye is common. Allergic contact reactions from phenylephrine are rare despite extensive use by ophthalmologists. Previous reports do not indicate crossreactivity between phenylephrine and other sympathomimetic drugs in patch testing. METHODS We report three cases of allergic contact reactions (dermato-conjunctivitis) after eyedrops. Skin prick tests, epicutaneous testing with the implicated drugs, additives, and a complete patch test battery, TRUE test (Upjohn-Pharmacia, Sweden), were performed in each patient. RESULTS All skin prick tests were negative. The three patients showed positive patch tests to phenylephrine and one of them also to ephedrine. Tolerance of the other eyedrops without phenylephrine was verified by challenge. CONCLUSIONS Phenylephrine was the responsible agent for the reactions in our patients as confirmed by clinical findings and positive patch tests. Our findings suggest the central structure as the sensitizing part of drug in the second patient. Patch testing is essential for diagnosis of allergic contact reactions of and around the eye.