Rationale:Bariatric surgery is the recommended treatment for morbid obesity because of its rapid and sustained body weight loss effect. Nutrient deficiency-related neurological complications after bariatric surgery are often disabling. Thus, early recognition of these complications is important. Neurological complications involving the central and peripheral nerve system after bariatric surgery were reported. However, the report on the clinical course of the concurrent involvement of central and peripheral nervous system is limited. We present a rare case of a patient who developed Wernicke encephalopathy concurrent with polyradiculoneuropathy after receiving bariatric surgery.Patient concerns:A 22-year-old man with a history of morbid obesity presented progressive bilateral lower limbs weakness, blurred vision, and gait disturbance 2 months after receiving laparoscopic sleeve gastrectomy. Bilateral lower limb numbness and cognition impairment were also noted.Diagnosis:Brain magnetic resonance imaging and electrophysiologic studies confirmed the diagnosis of Wernicke encephalopathy concurrent with acute polyradiculoneuropathy.Interventions:Vitamin B and folic acid were given since admission. He also received regular intensive rehabilitation program.Outcomes:The subject's cognitive impairment and diplopia improved 1 week after admission under medical treatments, yet lower limb weakness and gait disturbance were still noted. After a month of intensive inpatient rehabilitation, he was able to ambulate with a walker for 30 munder supervision.Lessons:Nutrient deficiency-related neurological complications after bariatric surgery are often disabling and even fatal. Prevention of neurological complications can be improved through close postsurgical follow-up of the nutritional status. Recognizing the signs and symptoms and evaluating the medical history are critical to the early diagnosis and treatment of this potentially serious yet treatable condition.