In the daily practice of allergology, one of our commonest problems concerns the prescription of nonsteroidal anti-inflammatory drugs for our patients who are intolerant of acetylsalicylic acid, whose basic clinical expression of this intolerance is primary bronchial asthma. Our problem is the high frequency with which the syndrome appears after the administration of other analgesics chemically unrelated to acetylsalicylic acid. Most authors accept that derivatives of pyrazolones and indoles, and of phenylisopropionic and anthranilic acids must be avoided. This avoidance is based on collected clinical experience and the currently accepted hypothesis concerning the pathogenesis of the syndrome (pyrazolones, indoles, etc. are inhibitors of the byosynthesis of the E series of prostaglandins, particularly PG synthetase). On the other hand there is no agreement concerning what type of analgesics, anti-inflammatory drugs and antipyretics we should prescribe for these patients. The conclusions of the protocol which we carried out are as follows. Dextropropoxyphene chlorhydrate, diviminol, tilidine chlorhydrate, salicylamide, benzidamine, pentazocine, isonixine, hyoscine bromide and ergotamine tartrate can be prescribed safely for these patients in the usual therapeutic dosage. To the list of prohibitions should be added the derivatives of glaphenine and phenylacetic acid. As regards paracetamol, our opinion is that its use should be restricted to those cases in which the previously listed drugs cannot be substituted for it, and always after administration under medical supervision in a hospital setting.