We present a case of bronchopulmonary sequestration suspected in the morphological ultrasound at 20 weeks of gestation based on the finding of a homogeneous hyperechoic triangular image in the left lung of the fetus, which was confirmed 2 weeks later with the observation of a blood vessel from the aorta feeding the mass. Due to the absence of poor prognostic factors, an expectant attitude was adopted, with a progressive decrease of the mass until its complete disappearance on ultrasound at 37 weeks.