Background: we examined how lung function and certain clinical and laboratory characteristics in asthmatic children were changed according to skin test positivity to aeroallergens. Methods: a skin prick test was conducted using standardized extracts of 10 different allergens in 56 children with bronchial asthma, aged 5-15 years, in Dicle University Hospital. Lung function was measured by Microplus spirometer. Results: among the 56 subjects, asthma was classified as mild in 16, moderate in 42 and severe in 3. At least one skin prick test was positive (monosensitized) in 35 subjects (62 %) and positive reactivity to two or more aeroallergens (polysensitized) was found in 17 subjects (30 %). Positive skin test reactions to aeroallergens were associated with a decrease (as percentage of the predicted decrease) in FEV1, FVC and PEF values. Significant differences were also found between prick test-positive and -negative asthmatics in duration of breastfeeding (8.5 5 months vs 15 7 months, respectively, p < 0.007), age at which cow's milk had been started (5.7 1.6 vs 10.5 5.4, p = 0.004); total serum IgE concentration (350 221 IU/ml vs 234 164 IU/ml, p = 0.02), age at onset of asthma symptoms (2.5 1.9 years vs 4.1 2.2 years) and number of asthma attacks per year (7.0 3.1 vs 5.2 3.5, p = 0.012). When one-way ANOVA and a post-Hoc test were used, asthma attacks were more frequent and severe and allergic conjunctivitis symptoms were more frequent in the polysensitized group than in the nonsensitized and monosensitized groups (p = 0.03). Conclusions: children with positive skin prick test results, especially those with combined sensitivity to dust mite, cat and dog, were at increase risk of more severe asthma.