Intrapulmonary sequestration is a rare disorder which should be considered when an intrathoracic mass is found in the lower part of the lungs. The clinical symptoms range, as in our two patients, from an asymptomatic mass in the chest X-ray film to frequent pulmonary infections. A definite diagnosis is possible only by visualization of the aberrant artery by arteriography, which is also helpful to the surgeon at lobectomy.