A 95-year-old female with a history of dementia and atrial fibrillation (not on anticoagulation) presented to the emergency department (ED) by ambulance from her skilled nursing facility due to hypoxia. Point-of-care ultrasound was performed, and showed evidence of a large mobile thrombus in the right ventricle on apical four-chamber view. Further evidence of associated right heart strain was seen on the corresponding parasternal short-axis view. These ultrasound findings in combination with the patient’s clinical presentation are diagnostic of acute pulmonary embolism with right heart strain. Point-of-care transthoracic cardiac ultrasound in the ED is an effective tool to promptly diagnose acute pulmonary embolism with right heart strain and thrombus in transit and guide further treatment.