Abstract The Intolerance towards Acetylsalicylic acid can reveal itself as acute urticaria, angiooedema, bronchospasmus, heavyrhinitis, anaphylactic shock. Study purpose Our clinical study aims to reveal the frequency and character of the Acetylsalicylic acid intolerance among patients suffering from bronchial asthma. Materials and methods The study enrolls 250 patients (18-83 years old) suffering from bronchial asthma, male - 112, female – 138. 120 show atopic bronchial asthma of them, 130 - non-atopic. The aspirin intolerance was suspected after detailed collecting of patients' data, anamnesis and history of illness. Results The Aspirin intolerance was surely proved by 31 of the study-enrolled patients – 12, 4%. The difference in the frequency of the Acetylsalicylic acid intolerance in male and female asthmatic patients doesn't show a significant importance – men - 11, 61 and women - 13, 04. Non atopic bronchial asthma tends to be far often accompanied by an aspirin intolerance – 20, 00%, while patients with atopic bronchial asthma suffer from Acetylsalicylic acid intolerance in just 4, 17% of the cases (p<0, 05). In patients with atopic bronchial asthma prevails the urticaria type of intolerance, while in patients with non atopic asthma the bronchospastic type shows to be more significant. 25 of the patients suffering from non-atopic bronchial asthma accompanied by Acetylsalicylic acid intolerance did undergo a hyposensibilisation with aspirin. Successful temporal desensibilization was achieved in 21 of them – 80, 77%.