BACKGROUND: Hospitalisations are important events in COPD, and exacerbation prevention strategies are not completely effective. Experience with our research cohort suggested that availability of 24-hour telephone advice may reduce hospital admission. AIM: To examine the use and utility of a 24-hour Telephone Support Service for high-risk NHS COPD patients. METHOD: 74 patients with 'high-risk' COPD had therapy optimised, were educated about exacerbations, given home 'emergency' therapy, and had 24-hour access to telephone advice. RESULTS: Patients had a mean (SD) age of 70.4 (9.1) years and severe disease (mean FEV1 1.00 (0.37) litre; 30% had home oxygen and 46% lived alone). There were 258 telephone calls in 22,074 follow-up days. 76% of calls were received between 0800 and 1700 hours. The proportion of possible exacerbation ('appropriate') calls (overall 56%) was higher at weekends and overnight. Overnight calls (2100- 0800) were rare: to expect one appropriate call per shift would require 2453 patients. A third of appropriate overnight calls could be managed without further emergency assessment. Mean (SD) length of follow-up was 298 (117) days/patient. Patients completing one year of follow-up (n=52) demonstrated a 45% reduction in admissions and 37% reduction in bed days. Patient satisfaction was high. CONCLUSIONS: We report data on the use and utility of a 24-hour Telephone Support Service in COPD. The service was associated with a reduction in hospital admission. Call volume was low, thus giving information on the size and cost-effectiveness of such service provision.