Between July 1985 and January 1990, pseudomonas scepticaemia occurred in 19 out of 584 patients with AIDS attending the Westminster and St Stephen's AIDS Unit, London, UK. Ten of these 19 were being treated for active cytomegaiovirus infection. Fourteen of the 19 patients had a central venous catheterin situ, which was the source of infection in 11. Seven patients died. Mortality was significantly greater in those patients infected withPseudomonas aeruginosa, in those patients whose source of infection was not the central venous line, and in those patients whose central line was not removed.