Allergic conjunctivitis is a very common disease in our country. We intend to determine the most frequent ocular involvement and the specific sensitivity to common aeroallergens. A longitudinal prospective study was performed on 20 patients from the allergy/immunology and ophthalmology outpatient service, Hospital Infantil de Mexico Federico Gomez, from May to July 1990. All of them had allergic conjunctivitis and were evaluated for ocular involvement and reactivity to common aeroallergens by skin prick test.