Morel-Lavallée lesions are uncommon injuries that can be associated with significant comorbidities if not detected early. Rapid diagnosis in the Emergency Department could significantly improve patient outcomes. We describe the diagnosis of such a lesion through the use of ultrasound imaging in the Emergency Department to utilize a fast, cost-effective imaging technique that does not subject the patient to radiation exposure. Our patient received surgical consultation but improved with conservative management. Ultrasound findings associated with this lesion do not require specialized equipment and should be considered when evaluating soft tissue lesions using point of care ultrasound.