AIM: To determine the prevalence of other allergies in patients with vernal keratoconjunctivitis(VKC) and their first-degree relatives.METHODS: This prospective study was done on 520 patients with VKC over a 9-year period from April 1999 to March 2008. All information such as age, sex, types of vernal and various types of other accompanying hypersen-sitivities in patients and/or their relatives were recorded on questionnaires and analyzed statistically.RESULTS: Among 520 patients, 369 (71.0%) were male and 151 (29.0%) were female. The mean age of patients was 15.3 years (6-30 years). 242 cases (46.5%) had history of vernal or other types of hypersensitivities in themselves or their first-degree relatives. Among these positive history cases ,68 patients (28.1%) had allergic dermatitis,51 cases (21.1%)vernal conjunctivitis (in their relatives),46 cases (19.0%)asthma, 29 cases (12.0%) allergic sinusitis, 24 cases (10.0%)drugs hypersensitivity, 14 cases (5.8%) atopic dermatitis, 6 cases (2.5%) allergic rhinitis and 4 cases (1.6%) had hay fever history.CONCLUSION: Many patients with VKC have other IgE-mediated or other types of hypersensitivity in him/her self and/or their relatives. Asthma, drug induced allergy and other hypersensitivities are common in these patients. The rate of vernal in relatives of patients was high, so it may be due to genetic origin of the disease.