Skin prick tests (SPT) were carried out on 164 asthmatic children using dog dander allergen preparations (A, B1, B2 and D) from three manufacturers. Bronchial and/or conjunctival provocation tests with allergen A were performed on all patients, as well as the Phadebas® RAST (allergen e5). There was a close agreement between the clinical history and the SPT with allergens A and D. The provocation tests and RAST gave results in good agreement with the SPT reactions to all allergens except B1. The overall agreement between the SPT reactions to the different allergens was good. However, significant differences were observed in the allergenic activity of the different preparations and between different batches from the same manufacturer (allergens B1 and B2).