The authors studied the incidence of drug allergy in 3 groups of subjects. In the first group the incidence was established in terms of the subjects' age: 1.8% in children up to 14 years old (323 subjects), 5.8% in middle-aged subjects (389 subjects) and 2.9% in the elderly (243 subjects). In the second partly selected group, drug allergy was studied in patients admitted to the 3rd Medical Clinic--Craiova between 2 Jan. 1981 and 31 Dec. 1982; 103 of the 8,760 patients admitted presented allergic reactions, a relatively high incidence rate (1.01%) as compared to other published reports. The third group of previously selected cases consisted of 197 patients who had come to the allergology service with complaints of present or past sensitivity to drugs. The total number of patients was 336 selected or preselected from about 10,000 subjects, to which 17 patients with a diagnosis of "asthmatic triad" must be added. Drug allergy in terms of the drug used was dominated by penicillin, pyramidon-algocalmin, aspirin, iodine preparations, etc.; foremost among the clinical syndrome were the dermatologic syndromes types I, III and IV; syndromes of the "anaphylactic shock" type, "serum sickeness" bronchial asthma, angioneurotic oedema.