A 5-day course of oral moxifloxacin has been shown in an Italian multicentre study to be at least as clinically effective, and more cost effective, than a 7-day course of IM ceftriaxone for treating patients with acute exacerbations of chronic bronchitis (AECB). This is an important finding given that the incidence of AECB is likely to rise as the world's population ages, and the number of people who smoke does not appear to be declining to any significant degree. Therefore, studies will be needed to help rationalise drug choices for patients with AECB, with the rationalisations focusing on efficacy, safety, ease of administration and cost effectiveness.