The annual number of confirmed cases of Legionnaires' disease in both Nottingham, and England and Wales, reached a peak in 1980 and has since declined. Legionella infection is a rare cause of community-acquired pneumonia managed at home (accounting for less than 1% of cases), more common in those admitted to hospital (5-15%) and more common still in patients with severe pneumonia as seen on an intensive care unit (up to 30% of cases). Antibiotic therapy for any patient with moderate or severe pneumonia of uncertain aetiology should cover legionella infection.