It is estimated that in patients with COPD malnutrition affects 10-15% of patients with mild to moderate stage of disease and 50% of patients with advanced stage of disease. Available studies indicate that weight loss and muscle mass loss are negative prognostic indicators, therefore early diagnosis of malnutrition seems to be a key measure in the treatment of COPD. In the article the authors discuss and compare the most commonly used methods to assess nutritional status and provide information on the impact of diet on risk of COPD in the future. Nutritional status of patients with COPD is difficult to assess. To date, no published standards are available. Reliable and accurate assessment of nutritional status is essential for planning further care and may contribute to the improvement of nutritional status and contribute positively to the course of the disease.