Wernicke-Korsakoff syndrome (WKS) is caused by severe thiamine (vitamin B1) deficiency and can lead to chronic deficits. In this case, a 22-year-old pregnant patient at 10 1/7 weeks of gestation presented to the emergency department with malaise, asthenia, headache, weakness, vomiting, and weight loss of 12 kg. Pancreatitis and hepatic steatosis were considered but ruled out, and cholecystolithiasis was confirmed by ultrasound. After significant neurological deterioration, the patient underwent a cranial MRI that revealed suggestive findings in the thalamus consistent with WKS. WKS is a rare complication of hyperemesis gravidarum and should be included in the differential diagnosis of persistent vomiting in order to initiate early and appropriate treatment.