Lung function was assessed in 17 panic patients and 20 healthy controls. Panic patients had abnormal values for some dynamic lung volumes, namely Peak Expiratory Flow Rate (PEFR), Expiratory Flow at 75% of Vital Capacity (FEF75) and Maximum Mid-Expiratory Flow Rate (MMEF). Such functional abnormalities might indicate subclinical obstruction of lung airways, possibly relevant to the mechanisms related to panic disorder (PD).