This study was designed to evaluate the frequency of respiratory allergens in different age groups of asthmatic atopic children in the Chieti-Pescara area. We examined a pediatric population (507 children) aged between 1 to 17 years (mean 6.62 +/- 2.9). All the children were submitted to a panel of skin prick tests (SPT) for 12 common aeroallergens: Grass Pollens (G.), Parietaria (P.), Olive (O.), Artemisia (A.), Ragweed (R.), Dermatophagoides Pteronyssinus and Dermatophagoides Farinae (D.P. & D.F.), Cat and Dog dander (C.D.), Feathers (F.), Alternaria (Al.), Aspergillus (As.). All the subjects gave positive result to one or more allergens. The population was subdivided in to 4 groups according to their age (Group A: 1-3 years; Group B: 4-6 years; Group C: 7-9 years; Group D: 10-17 years). In each age group, we determined the number of subjects with 1, 2, 3, 4 or 5 and more than 5 positive SPT and the prevalence of positive SPT for different allergens. We found that 74% of 507 patients showed positive reaction to Dermatophagoides Pt, 71% to Dermatophagoides Fa, 45% to Grass, 23% to Parietaria, 21% to Olive, 17% to Artemisia, 17% to Cat's or Dog's danders, 13% to Alternaria, 5.9% to Ragweed, 5.9% to Feathers, and 4% to Aspergillus. In addition we detected that 12% of children examined were monosensitized; 56% were sensitized to 2 or 3 allergens; 22% were sensitized to 4 or 5 allergens, and then 8% were polysensitized to > 5 allergens. The allergy to grass pollens and to house dust mites was the most frequent in monosensitized. In the older patients, we found an increase in number of positives SPT to several allergens, and an increase in the frequency of Gr., P. and O. allergy, while the house dust mites sensitization remained constant in all groups and represented the dominant cause of asthmatic symptoms in this population. Our data confirm the importance of age in determining a respiratory polysensitization. In conclusion, our data suggest that house dust mites (D.P. and D.F.) and grass pollens are the most common allergens in asthmatic children of the Chieti-Pescara area.