The prevalence of positive skin prick tests to the mite species Dermatophagoides pteronyssinus, D. farinae, Blomia tropicalis, Chortoglyphus arcuatus, Lepidoglyphus destructor and Aleuroglyphus ovatus was determined in 297 asthmatic adults and children living in seven cities of five Latin American countries. A standardized protocol and a common battery of extracts were used at each site. The mean wheal diameters were measured after 15 min, and those > or = 3 mm were considered positive. Sensitization to D. pteronyssinus varied from 60.7% in Cartagena to 91.2% in São Paulo; to D. farinae from 53.3% in Córdoba to 97.2% in Caracas; to A. ovatus from 26.6% in Bogotá to 71.2% in São Paulo; to B. tropicalis from 46.5% in Mexico City to 93.7% in São Paulo; to C. arcuatus from 33.3% in Mexico City to 75% in São Paulo; and to L. destructor from 30% in Mexico City to 76.2% in São Paulo. This study reported the results of skin test sensitivities in both children and adults. The studies from São Paulo and Córdoba were confined to children and thus could be compared; there was a significantly higher prevalence of cutaneous sensitivity to mite allergens in the children of São Paulo than in those of Córdoba (p < 0.001 for all mite species). Cutaneous sensitivity to mite allergens is very common in young and adult asthmatics in Latin America, in areas both at sea level and at high altitudes. Environmental control measures should be reinforced in the treatment of asthmatics in Latin America.