10 patients (mean age 23.1, range 17.1-40.5 years), 8 with cystic fibrosis (CF), and 2 with advanced bronchiectasis without CF, were taught, while being treated in hospital for exacerbations of pseudomonas infection, how to continue to give themselves intravenous antibiotics at home. They were discharged after satisfactory antibiotic levels had been achieved, and 22 courses were given at home over a total of 116 patient-days. In 14 of these, the greater part of the course was given at home (mean duration 6.6, range 5-10 days); 2 of these were given without admission to hospital. In the 8 patients with two or more infective exacerbations within a 12-month period there was no difference between home and hospital treatments in clinical improvement or in relapse time, defined as the interval between completion of treatment and subsequent antibiotic therapy. Self-administration of antibiotics intravenously at home for selected adults with cystic fibrosis and severe bronchiectasis reduces hospital stay and does not seem to be associated with an increased rate of recurrent infection.