Proboscis lateralis (PL) is an extremely rare congenital facial anomaly that can be diagnosed prenatally. There are a wide variety of craniofacial and cerebral anomalies that can be associated with this condition that have important implications, both aesthetic and functional. Moreover, there are cases associated with severe anomalies that can lead to perinatal mortality. Significant advances in ultrasound techniques, both two- and three-dimensional, allow an accurate diagnosis of this type of malformation, improving prenatal assessment. Postnatal treatment is complex and must be individualized according to the characteristics of each case. We present a case of PL that was diagnosed prenatally and describe the prenatal ultrasound features, associated structural anomalies, and postnatal imaging and outcome. When a facial anomaly is found prenatally, an exhaustive examination of all craniofacial and cerebral structures is indicated due to the strong association with other facial and brain abnormalities. A multidisciplinary approach is also important in these cases.