Background: Pathological alterations in nutritional status may develop in Chronic Obstructive Pulmonary Disease (COPD) patients through production of inflammatory cytokines and inadequate diet. Objective: The aim of our study was to determine the correlation between nutritional status and quality of life of COPD patients. Methods: We evaluated the nutritional status of COPD patients of Hungarian National Koranyi Institute for Pulmonology using the Malnutrition Universal Screening Tool (MUST) and bioelectrical impedance analysis (BIA) between January 1 and June 1, 2019. Lung function, physical fitness, and respiratory muscle strength were included in the assessment. Results: Fifty patients (mean age was 66.3 +- 9.6 years) participated in our study. Mean body mass index (BMI) was 26.2 +- 6.1 kg/m2 and mean fatfree mass index (FFMI) was 16.8 +- 2.4 kg/m2. Overweight patients had better lung function values (FEV1ref %: 46.3 +- 15.2) than normal (FEV1ref%: 45.1 +- 20.9) and underweight patients (FEV1ref%: 43.8 +- 16.0). The Modified Medical Research Council Dyspnea Scale (mMRC) was significantly associated with various parameters; strongest correlation was found with FFMI (r 5
0.537, P < 0.001), skeletal muscle mass index (SMMI) (r 5
0.530, P < 0.001), and 6-minute walking distance (6MWD) (r 5
0.481, P < 0.001). Conclusions: Our results indicate that malnourished COPD patients may have reduced lung function and lower quality of life compared to normal weight patients. Thus, our findings suggest that nutritional therapy be included in the treatment of COPD patients combined with nutritional risk screening and BIA during the follow-up.  Kulcsszavak: chronic obstructive pulmonary disease, bioelectrical impedance analysis, body-mass index, fat-free mass index, nutritional status