The diagnosis of aspirin exacerbated respiratory disease (AERD) is principally based on typical history. The aim of this study was to evaluate the applicability of measurement of LTE4 concentrations in urine by using ELISA method in diagnosis of AERD. In addition, an analysis of clinical and other laboratory data was carried out to verify their role in AERD diagnosis. The study comprised 3 groups of subjects over 18 years of age: patients with AERD (n = 247), patients with ATA (n = 239) and healthy subjects (n = 95). A detailed medical questionnaire was carried out with all patients. In addition subjects underwent: spirometry with reversibility test, skin prick tests with common aeroallergens, measurement of total IgE and eosinophil count in blood, as well as LTE4 concentration in urine by ELISA method. The analysis carried in this study shows that measurements of LTE4 concentrations in urine as a single parameter for AERD diagnosis has too low diagnostic value to be used in clinical practice. Next to typical history of hypersensitivity reactions to NSAIDs, the best clinical predictors of AERD diagnosis were the following parameters: symptoms caused by upper airway involvement, nasal polyps formation, frequent asthma exacerbations and bronchial obstruction.