The objective of the present post-marketing surveillance (PMS) was the evaluation of efficacy, tolerability and acceptance of the novel budesonide (CAS 51333-22-3) multidose dry powder inhaler (MDPI) Novopulmon 200 Novolizer. A total of 3,057 patients suffering from allergic, non-allergic or mixed bronchial asthma were included in the PMS. The study medication was administered by inhalation at a median dosage of 2 x 200 micrograms budesonide/day. In order to evaluate the efficacy of the novel budesonide MDPI, pulmonary functions (peak expiratory flow rate (PEFR) and FEV1) were measured at the start of the treatment and after 4 weeks of treatment. Severity of the following symptoms was evaluated on a four-score scale: cough, wheezing, diurnal dyspnea, nocturnal dyspnea and dyspnea on physical effort. Furthermore, the patients' satisfaction in dealing with the control mechanisms (optical, acoustic, sensory, dose counter, overdose prevention) of this innovative MDPI was assessed. Patients who already had used another inhalation system assessed the control mechanisms of the novel budesonide MDPI in comparison with their previous inhalation system (e.g. fluticasone premetered dose MDPI, non-refillable budesonide MDPI). The patients' compliance and any improvement of compliance by the control mechanisms according to physicians' assessments were evaluated. The novel budesonide MDPI was shown to lead to a decrease in the severity of symptoms. The median total symptom score (0 = no symptoms, 15 = all symptoms severe) decreased from 8 before therapy to 2 after therapy. Pulmonary function measurements supported a relief of the patients' symptoms: The median PEFR increased from 5 l/s before therapy to 6.3 l/s at the end of therapy, with a median individual increase of 1 l/s. The median FEV1 increased from 2250 ml before therapy to 2700 ml at the end of therapy, with a median individual increase of 310 ml. The majority of patients were satisfied with the control mechanisms. 97% of the patients were satisfied with the optical control mechanism, 94% with the acoustic, 78% with the sensory mechanism, 92% with the dose counter and 81% with the overdose prevention. Compliance was assessed by the physicians to be good in 84% of the patients, to be satisfactory in 14% and to be not satisfactory in 2%. An improvement in compliance by the control mechanisms of the inhaler was observed in 80% of the patients. 97% of the patients were satisfied with the control mechanisms, the optical and acoustic mechanisms were confirmed as being the most important ones. The vast majority of patients assessed the control mechanisms of the novel MDPI to be better or much better than those of a previously used inhaler (e.g. 41.2% and 52.1%, respectively, of patients who had previously used a non-refillable budesonide MDPI; 38.7% and 44.7%, respectively, of patients who had previously used a fluticasone premetered dose MDPI). Overall, the novel budesonide MDPI was shown to be efficient in the relief of asthma symptoms and improvement of lung function. The MDPI's control mechanisms were shown to be well accepted by the patients and considered by the physicians as an important contributor to an improvement of patient compliance.