BACKGROUND Acute aortic dissection (AAD) is a rare but life-threatening condition with high mortality. The Stanford classification of aortic dissection includes type A, which originates in the ascending aorta, and type B, which originates in the descending aorta. The diagnosis may be missed due to its ability to mimic other more common cardiovascular conditions. A case is presented of late diagnosis of AAD involving the right carotid arteries in a 55-year-old man who presented with acute ischemic stroke. CASE REPORT A 55-year-old man presented with sudden onset of left-sided facial weakness and aphasia. He was diagnosed with acute ischemic stroke and treated with tissue plasminogen activator. Further imaging showed an AAD involving the entire length of the aorta. Treatment with tissue plasminogen activator was discontinued, and the patient underwent surgical repair of the aorta. His hospital stay was complicated by acute kidney injury (AKI), pneumonia, and sepsis, and he died three weeks later from renal failure. CONCLUSIONS This case demonstrated that AAD can be challenging to diagnose, and may present atypically with ischemic stroke when it involves the carotid arteries. In such cases, imaging studies of the chest, abdomen, and head and neck may identify AAD and prevent inappropriate treatment with anticoagulants.