Allergic disorders are characterized by Th2-polarization, and hence physiological Th1-dependent mechanisms for fighting respiratory infections (RI) may be defective. This study aimed at evaluating the number and duration of RI in allergic and non-allergic children suffering from recurrent RI. One hundred seventeen children (4.02 +/- 1.0 yr, 72 males and 45 females) were studied during the spring, 46 were allergic. Allergic children showed a significantly higher number (mean 1.26 +/- 0.73) and longer duration of RI (8.92 days) in comparison with non-allergic group (0.94 +/- 1.37 and 4.85 days) (p = 0.0001 and p = 0.009, respectively). In conclusion, this study provides the evidence that allergic children have more numerous and severe RI than non-allergic children.