A 51-year-old man diagnosed with Plasmodium vivax malaria was transferred to our clinic with newly developed drowsy mentality and myoclonus after the initiation of hydroxychloroquine therapy. Following therapy to treat the vivax malaria and supportive care, the patient recovered completely with no sequelae. Cerebral complications caused by vivax malaria are very rare worldwide, and only two cases have been reported in Korea. Here, we report the third published case of P. vivax infection with cerebral complications in Korea. (Korean J Med 2012;82:382-385)