Wheezing is a lung sound phenomenon observed during bronchial obstruction. Here, bronchial asthma is most relevant. Issues Aim of the present thesis was to detect wheezing during provoked bronchial obstruction. Further it was questioned if the occurrence of wheezing leads to higher specic airway resistance and, vice versa, if a increasing specic airway resistance leads to wheezing. Materials and Methods For 25 patients, 7 female and 18 male (age 4318a), with bronchial asthma or a hyper-responsive bronchial system methacholine provocation tests according to the guidelines of the German Society of allergology and clinical immunology were conducted. After each provocation level lung function parameters were measured. The lung sounds were recorded and subsequently the results were compared with measured lung function parameters. Results For 9 out of 25 patients wheezing was observed. Wheezing was found for 5 patients without provocation and for 4 patients after provocation. Non of the patients ever showed wheezing after broncholysis. The threshold of the specic airway resistance for the occurrence of wheezing is sRtot = 2,0kPa/l/s. In the group of non-wheezing patients no wheezing was found for 8 out of 16 Patients even though the sRtot did exceed 2,0kPa/l/s. For patients with wheezing a signicant steeper increase of the specic airway resistance in comparison with the group of non-wheezing patients is found. Discussion Although double-sided wheezing is always an indication for a bronchial obstruction (own investigations), the results presented here prove the specic airway resistance is not suited to predict the occurrence of wheezing.