Clavicle fractures are the most common bony injury that occurs during the delivery process. We present a case of medial clavicular physeal fracture mimicking sternoclavicular dislocation diagnosed by ultrasound (US) in a neonate. The infant presented to our clinic at 12 days old with improving left upper extremity pseudoparalysis and outside radiographs interpreted as left sternoclavicular dislocation. US demonstrated a displaced physeal fracture rather than a dislocation. The radiologist should be aware of this potential distinction. Our case shows the usefulness of US in obtaining the definitive diagnosis without the need for radiation or sedation, demonstrates a unique use of this modality, and illustrates that US should be considered for clarification in future cases of suspected sternoclavicular injury in the neonate.