Case summary: A 19-year-old Saudi male morbidly obese patient (BMI 48 kg/m2). The patients underwent sleeve gastrectomy 5 months ago and cholecystitis 1 month ago. The patient presented to our emergency department (ER) with all limb numbness in the last 3 weeks, difficulty walking, blurred vision, headache, and nausea for the last week. The patient was diagnosed with Wernicke encephalopathy based on his symptoms, physical signs, and classical MRI brain findings. Conclusion: Bariatric surgery can complicate Wernicke encephalopathy, associated with thiamine deficiency. Prophylactic thiamine supplements can prevent the subsequent bariatric WE condition.