Pneumonia due to Escherichia coli (E. coli) has a reported mortality of up to 70 per cent. Most infections are associated with underlying disease, and follow bacteraemia from a genitourinary or gastrointestinal source. This report describes two patients with bacteraemic E. coli pneumonia, presumed secondary to aspiration of E. coli from the oropharynx. Both patients presented a rapidly progressive illness with hypotension. Response of the pneumonia to early, appropriate antimicrobial therapy, was complete. Our cases are discussed with particular reference to clinical features of the infection and choice of antimicrobial therapy.