Background: Latex allergy is a major occupational disease with prevalence nearly 5-17% among the health care workers. Objective: To determine the prevalence of latex glove allergy and its contributing factors among operation room staff. Patients and Methods: In this study, 512 operation room staff were evaluated for latex allergy, using a complete questionnaire. Those suspected to have latex allergy underwent these tests: Eosinophils counting, measurement of serum total and latex specific IgE, latex skin prick test, latex and glove additives patch test. Results: From evaluated staff, 178 (34.8%) had a history of sensitivity to latex gloves, from which 59 persons underwent the tests voluntarily. According to the results of the tests, 13 (22%) had type I allergy to latex, 3 (5.1%) had type IV allergy to latex and 9 (15.3%) had both allergies. There were no significant relationship between latex allergy and age, sex, job, season, family and personal history of allergies. Significant relationship was found between type I allergy to latex and allergy to kitchen gloves and also between type IV allergy and allergy to other plastic clothing. Conclusion: Prevalence of latex allergy in this study is much higher than similar studies, which demands more evaluation to determine the contributing factors.