Undernutrition, a common but treatable complication of chronic obstructive pulmonary disease (COPD), contributes to poor outcomes but is under-detected. Improved detection could prompt dietary intervention which may improve outcomes. We investigated whether adding a measure of muscle mass (fat-free mass index, FFMI) or a malnutrition screening tool (Mini Nutritional Assessment, MNA®) to the commonly used measure of body mass index (BMI), helps detect undernutrition in COPD.We conducted a retrospective chart review of 86 outpatients with COPD. Demographic and disease severity data were collected, and nutritional status assessed using BMI, FFMI and MNA®.Patients comprised 55% males with median age 71.5 years, severe COPD (median FEVThe MNA® identified more undernourished patients than FFMI or BMI. It also correlated with disease severity and broader symptom burden. The MNA® appears to be a simple tool for earlier detection of patients who may benefit from dietary intervention, potentially enhancing their quality of life.