The distinction between a ventricular aneurysm and diverticulum is difficult. The differences between these two are based on anatomical, histological, and functional criteria. We present a case of prenatal diagnosis of a giant left ventricular outpouching at 28weeks gestation. During the postnatal period, the neonate underwent surgical correction for the outpouching. Histopathological examination reported the resected segment was a cardiac diverticulum. Our case indicates that differentiating between the two diagnoses during the intrauterine period is not always straightforward and possible. Histopathological examinations are sometimes necessary to make a precise differentiation. Treatment should be individualized depending on the clinical presentation.