Yellow sputum is formed in the pathology of the bronchopulmonary system: acute and chronic purulent bronchitis, chronic obstructive pulmonary disease, lung abscess and bronchiectasis. Rare causes of the symptom include pulmonary eosinophilia, foreign bodies in the respiratory tract, oncological and congenital diseases. The diagnostic plan includes radiography and CT of the chest, bronchoscopy, spirometry, peak flowmetry. From laboratory methods, sputum examination, clinical and biochemical blood tests are used. Treatment is mainly medical - antibiotics, expectorants, bronchodilators and hormones. Operations are carried out if necessary.