The intention of the study was to determine nutritional state and body cell mass in patients with COPD in comparison with healthy volunteers between 50 and 75 years of age. Therefore, body cell mass (BCM), phase angle and the relation between extra cellular mass and body cell mass ECM/BCM was measured with the help of bioelectrical impedance analysis (BIA). While 10.4 % of COPD patients (male 5.0 %, female 18.8 %) had a BMI of < 18.5, no subject was underweight in the healthy volunteers. Overweight was found in 31.7 % patients (male 36.0 %, female 25.0 %) and in 54.2 % healthy subjects (male: 62.5 %, female 46.9 %), 17.1 % of our patients (male 16.0 %, female 18.8 %) versus 21.7 % of healthy subjects (male 14.3 %, female 28.1 %) were obese. While there was no statistic significance for a lower BMI in COPD patients, there were significantly decreased values concerning muscle mass -- represented by BCM-values -- and state of nutrition -- represented by BCM, phase angle and ECM/BCM values -- in COPD patients compared with healthy volunteers. These results suggest that BMI alone doesn't allow conclusions regarding to nutritional state and physical training. A malnutrition requiring intervention might exist in spite of a normal or even high BMI in COPD patients.