Acetylcholine, serotonin, and histamine levels have been measured in exhaled air humor condensate in 65 patients aged 18 to 60, 44 ones with bronchial asthma and 21 with preasthma. Nonuniform release of biogenic amines and acetylcholine in pulmonologic patients depended on the severity of the inflammatory process in the bronchi, hypoxemia, bronchial obstruction, and reactivity of the bronchi examined during cold air breathing.