BACKGROUND: Achievement of optimal asthma control is the goal of the Global Initiative for Asthma (GINA) guidelines. METHODS: In a survey involving 281 physicians, asthma control was assessed using the Juniper asthma control questionnaire (ACQ); physicians were also asked to judge patients' asthma control subjectively. RESULTS: In total, 2127 patients were included. Follow-up was available in 1893 (89%) patients (885 females). The mean time between visits was 62 +/- 29.3 days; mean age was 45 years (+/- 19 years) and 30% were smokers. Well-controlled asthma was found in 298 patients (16%). Smokers were less likely to have well-controlled asthma (smokers 12% vs. non-smokers 18%). Physicians assessed asthma control to be good in 292 patients (15%), sufficient in 504 (27%), insufficient in 954 (50%) and poor in 137 (7%) patients. Of the 292 patients assessed by their physicians as 'good asthma control', only 142 (49%) were confirmed as 'well-controlled' by the ACQ. At the first visit, 1308 (69%) patients were pre-treated with any inhaled corticosteroids (ICS). Pretreatment with leukotriene receptor antagonists (LTRAs) was reported in 127 patients (7%). Add-on therapy with the LTRA montelukast was the most frequent treatment adjustment at the first visit. Out of 1893 patients who had a follow-up visit, 298 (16%) were well controlled at the first visit and 1170 (62%) at the follow-up visit. CONCLUSION: Asthma control is insufficient in the majority of patients. Improvement of asthma control can be achieved by using objective measures such as the ACQ in regular clinical practice and adapting therapy.