OBJECTIVE: The objective of this study was to compare rates of different types of acute exacerbations of COPD (AECOPDs) and healthcare utilization among patients with different severities of COPD. METHODS: Data for this study was obtained from theHARMO Database Network, which includes drug dispensing records from pharmacies, hospitalization records and information from general practitioners. Patients with moderate to very severe COPD (GOLD II-III-IV) and a moderate or severe AECOPD between 2000 and 2010 were included in the study. Moderate and severe AECOPDs were defined by drug use and hospitalizations respectively. Study patients were followed from the first AECOPD to end of registration in PHARMO, death or end of study period, whichever occurred first. During follow-up, all recurrent AECOPDs were characterized and healthcare utilization was assessed. RESULTS: Of 886 patients in the study, 52% had GOLD-II, 34% GOLD-III and 14% had GOLD-IV. The overall AECOPD recurrence rate per person year (PY) increased from 0.63 for patients with GOLD-II to 1.09 for patients with GOLD-III and 1.33 for patients with GOLD-IV. The rate of severe AECOPD was 0.06, 0.14 and 0.17 per PY, respectively. CONCLUSION: AECOPD recurrence rates and healthcare utilizationare significantly higher among patients with more severe COPD.