Pulmonary sequestration is a congenital malformation in which the pulmonary parenchyma is isolated from the rest of the lung and receives irrigation. Traditionally this malformation has been diagnosed by arteriography, but in recent years the usefulness of magnetic resonance, a technique that can probably substitute for arteriography on many occasions, has been emphasized. We report 3 cases of intralobar pulmonary sequestration diagnosed by magnetic resonance, a procedure that provided adequate presurgical assessment. The magnetic resonance images were later shown to be consistent with anatomical findings.