Eleven general practitioners performed skin prick tests for specific pollen allergy (birch, timothy and mugwort) in 109 patients. One to two weeks later all 109 patients were skin prick tested again by one and the same very experienced nurse in a specialised allergy clinic. The results of the allergy-nurse were defined as "the real values". When the two sets of skin prick test were compared, 272 (83%) of all 327 skin pricks were of same size and class compared with the positive histamine-references. Forty-eight skin pricks (14%) were marginally different. Three skin prick tests (1%) were falsely positive and four (1%) were falsely negative. The study shows that general practitioners can after a short time of education and training perform and classify skin prick testing with great performance and at the same level as specialised allergy clinics. Skin prick test is a good supplement to clinical examination in general practice in the diagnosis of specific allergy in rhinoconjunctivitis and asthma bronchiale and in making suitable referrals to specialised allergy clinics.