We wanted to investigate whether home intravenous antibiotic treatment of pulmonary exacerbations of cystic fibrosis is as effective as treatment in hospital. The case records of all patients attending the Leeds adult cystic fibrosis clinic were reviewed to identify those who had received home intravenous antibiotic treatment. All home treatments undertaken were included. For each home treatment, the temporally closest hospital treatment for that patient was then selected for comparison and the changes with treatment in peak expiratory flow rate (PEFR), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), C-reactive protein (CRP), plasma viscosity, total white cell count, absolute neutrophil count, total immunoglobulin G (IgG) concentration, chest X-ray score (Northern), clinical score, Shwachman-Kulczyki score and weight were analysed for differences between home treatment and hospital treatment. Fifty one paired home/hospital treatments in 25 patients were compared. The improvement in total white cell count was found to be significantly greater in the hospital group, but the difference was very small. The improvements in absolute neutrophil count, and all the other measured variables, were the same in the two groups. Treatment of exacerbations of cystic fibrosis at home or in hospital is, thus, equally effective given proper patient selection and adequate monitoring of the response to treatment.