Chronic obstructive pulmonary disease (COPD) patients may suffer from symptoms of anxiety and depression. Whether and to what extent symptoms of anxiety and depression may be present in COPD patients entering pulmonary rehabilitation and which patient characteristics are associated with psychological distress remains currently unknown. The objective of the present study is to determine the prevalence and the determinants of clinically relevant symptoms of anxiety and depression in COPD patients entering pulmonary rehabilitation. Symptoms of anxiety and depression have been assessed in 701 COPD patients entering pulmonary rehabilitation using the Hospital Anxiety and Depression Scale. Additionally, disease-specific health status, pulmonary function, body composition, exercise capacity, co-existing morbidities, smoking status, symptoms, long-term oxygen therapy and the use of antidepressant and anxiolytic drugs have been recorded. Patients had mean anxiety scores of 7.6 points and mean depression scores of 7.2 points. Anxiety scores >or=10 points were present in 225 patients (32%) and depression scores >or=10 points were present in 192 patients (27%). Patients at risk of having symptoms of anxiety were female or used antidepressant or anxiolytic drugs. Patients at risk of having symptoms of depression experienced dyspnea, had a body mass index (BMI) <21 kg/m(2) or used antidepressant or anxiolytic drugs. A considerable proportion of the COPD patients entering pulmonary rehabilitation report symptoms of anxiety and/or depression, which may significantly impair disease-specific health status. Patients at risk of having symptoms of anxiety and/or depression are female, experience dyspnea, have a low BMI or use antidepressant and/or anxiolytic drugs.