Objective: Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of mortality worldwide and it remains under-diagnosed. Unrecognized somatic disease contributes significantly to the observed increased mortality rate in patients with psychiatric diseases.Aims: To investigate whether screening with spirometry and simple questions on respiratory symptoms were efficacious in identifying previously unknown cases of COPD and/or asthma in patients admitted to psychiatric wards.Methods: In this observational cohort study, we included hospitalized psychiatric patients in2013. All were assessed with handheld spirometry, medical history and completion of a simple, short questionnaire on respiratory symptoms, the COPD assessment test (CAT questionnaire).Results: In total, 106 patients were screened and 45 patients (age: median 45, range 19-75, 43% female gender) were included whereas 61 patients (age: median 42, range 19-73) 34% female gender) were excluded. Prior to screening three patients (6.5%) reported having a diagnosis of COPD whereas eight patients (17%) reported having a diagnosis of asthma. Six new cases were diagnosed with COPD and four new cases with asthma. The number needed to screen to find one new case was 3.4 (total cohort 4.5).Conclusion: We present a simple study where the patients are screened for obstructive lung disease with a handheld spirometry and a questionnaire on respiratory symptoms. Number needed to screen is low at 3.4-4.5. In all, 10 new cases of obstructive lung disease were diagnosed. This study illustrates that screening for COPD and asthma is feasible even in a psychiatric population.