The aim of this study was to evaluate the prevalence of asthma among 4-17 years old school children and to determine the relationship between frequent tonsillitis, tonsillar hypertrophy and asthma-related symptoms. A total of 2,000 school children, aged 4-17 years, in Denizli were surveyed using the ISAAC questionnaire; the size of the tonsils was evaluated by physical examination. A total of 1,784 questionnaires were completed giving an overall response rate of 89.2%. The prevalence of lifetime wheezing, 12-month wheezing and lifetime doctor-diagnosed asthma were 16.4%, 6.2% and 1.7%, respectively. The prevalence of frequent tonsillitis and tonsillar hypertrophy were 19.9% and 3.4%, respectively. Tonsillar hypertrophy was positively correlated with a history of frequent tonsillitis. Frequent tonsillitis and tonsillar hypertrophy could be evaluated as risk factors for asthma due to their significant association with asthma-related symptoms
