Asthma and chronic obstructive pulmonary disease (COPD) can be effectively treated by the use of bronchodilator therapies delivered by inhalation. Berodual is a fixed combination of the anticholinergic agent ipratropium bromide (IB) and the beta2-adrenergic agonist fenoterol hydrobromide (FEN). IB/FEN has been available for the treatment of asthma and COPD in a pressurised metered dose inhaler (MDI) [pMDI] formulation for many years. The pMDI is the most widely used device for the delivery of inhaled medications, such as IB/FEN. However, most conventional pMDIs contain chlorofluorocarbon (CFC) propellants, which are currently being withdrawn because of their detrimental effects on the environment. This has resulted in alternative methods of drug delivery being developed. Respimat Soft Mist Inhaler (SMI) is a new generation, propellant-free inhaler that generates a fine, slow-moving cloud (the Soft Mist) which can be easily inhaled. Scintigraphic studies have shown that this improves deposition of drugs in the lung and results in less oropharyngeal deposition than the CFC-MDI. A clinical development programme has been conducted to compare the efficacy and safety of IB/FEN delivered via Respimat SMI with that of IB/FEN via CFC-MDI in the treatment of patients with asthma or COPD. Five clinical studies (two phase II and three phase III) investigated dosages of IB/FEN 5/12.5 microg to 320/800 microg via Respimat SMI in single and multiple dose administration regimens. Four of the trials were conducted in patients with asthma (three in adults and one in children), while one phase III trial was conducted in patients with COPD. In phase III, 2058 patients participated, with a total of 1112 patients treated with IB/FEN via Respimat SMI. In the phase III studies, each dose from Respimat SMI was given in one actuation compared with two actuations with the CFC-MDI. In the paediatric asthma phase III study, all CFC-MDI doses were delivered via a spacer device. The results of the trials demonstrated that IB/FEN via Respimat SMI allows a reduction in the nominal dose of IB/FEN, while offering similar therapeutic efficacy and safety to a CFC-MDI. In children, Respimat SMI obviates the need for a spacer.