Acute bronchitis commonly associated with cough is predominantly caused by viral infections. The burden on health-care systems and society is enormous. A randomised, placebo-controlled, multicentre clinical trial to investigate the efficacy and safety of a liquid herbal drug preparation from the roots of Pelargonium sidoides (EPs 7630) was conducted in 217 adult outpatients with acute bronchitis. The primary efficacy variable was the bronchitis symptom score (BSS) ranging from 0 to 20. Primary data of this study were already published in 2007. Now, we present further analyses of these already published data combined with new results in order to focus on both the most important features of acute bronchitis and pharmaco-economic aspects of the disease. The BSS decreased by 7.6 +/- 2.2 (mean +/- SD) points for the active treatment group and 5.3 +/- 3.2 points for placebo (p < 0.0001). As compared with placebo, a marked improvement has been shown for EPs 7630 for all disease symptoms (cough, sputum, rales, dyspnoe, pain on coughing, hoarseness, headache, fatigue, fever, limb pain) categorised in severity classes by the patient. Especially strong antitussive and "anti-fatigue" effects with an early onset during treatment were observed. Patients in the EPs 7630 group were sooner able to work and to a lesser extent confined to bed. In both treatment groups, 3 x 30 drops of the trial medication administered for 7 days were well tolerated. No serious adverse events have been observed. In conclusion, EPs 7630 is superior to placebo in the treatment of acute bronchitis and leads to faster remission of bronchitis related symptoms.