Pyogenic lung infections still occur despite the availability of effective antibiotics for the treatment of patients with acute bacterial pneumonia. Our understanding of the pathogenesis and management of these conditions has steadily improved over the past few decades, although some areas remain obscure. The effect of HIV infection on the incidence of pyogenic lung infections remains largely unknown, and large studies are required to evaluate this. Burkholderia (formerly Pseudomonas) cepacia strains are now recognized as important respiratory pathogens in patients with cystic fibrosis, and the high transmissibility of some strains, combined with their inherent multiple antibiotic resistance, are continuing causes for concern.