Wernicke's encephalopathy is a potentially lethal complication of thiamine deficiency which mainly occurs in chronic alcoholic patients. It may occur in other conditions like hyperemesis gravidarum too. Pregnancy may also be complicated with other neurological and cardiac complications. Here we present a rare case of hyperemesis gravidarum in a primigravida patient with twin pregnancy having Wernicke's encephalopathy, central pontine myelinolysis and recurrent supraventricular tachycardia. This 20-year-old lady had all the classic features of Wernicke's encephalopathy like confusion, nystagmus, ophthalmoplegia and ataxia. Empirical treatment was given with parenteral thiamine. MRI of the brain was suggestive of Wernicke's encephalopathy. She had transient dysphagia. MRI of the brain also revealed central pontine myelinolysis, which was the most likely cause of this dysphagia. With treatment, her condition improved significantly, supraventricular tachycardia was also corrected. This case warrants careful monitoring and treatment of hyperemesis gravidarum patients to prevent such complications.