The current study aimed to assess the impact on patient health status during an acute exacerbation of chronic obstructive pulmonary disease (AECOPD).A total of 421 COPD patients were enrolled in a multicentre, single-arm study with a 6-month observational follow-up period. Patients received two inhalations of Symbicort 200 Turbuhaler1 twice a day. Patients were assessed before the run-in period, at baseline and at 1, 3 and 6 months. Patients were instructed to report a change in respiratory symptoms lasting .24 h. This defined an AECOPD. In addition to the initial call, the St George's Respiratory Questionnaire (SGRQ), COPD Control Questionnaire (CCQ), Medical Research Council (MRC) dyspnoea scale and activities of daily living (ADL) were completed at 5-7 and 12-14 days.A group of 176 patients reported at least one AECOPD. Exacerbations were associated with statistically significant mean changes (worsening) in the SGRQ activity and impact domains at onset (mean¡SD 12.1¡18.1 and 14.0¡15.2), during the first (9.8¡19.0 and 9.4¡16.6) and second weeks (3.1¡15.5 and 3.3¡14.7). Clinically significant deterioration in SGRQ impact scores was shown in 71% of patients following early identification, with 55 and 37% during the first and second weeks of an AECOPD, respectively.Acute exacerbation severely impacts on health status. The current study provides valuable information on the change in health status during an acute exacerbation of chronic obstructive pulmonary disease that can be utilised for future trials that evaluate therapeutic intervention.