Thiamine-responsive megaloblastic anemia syndrome is a rare autosomal recessive disorder defined by the occurrence of megaloblastic anemia, diabetes mellitus, and bilateral sensorineural deafness, responding in varying degrees to thiamine treatment. We report a precedence case for the treatment of deafness associated with the typical triad of thiamine-responsive megaloblastic anemia in a 4-year-old boy who showed a poor use of preoperative hearing aids but demonstrated significant improvements in hearing ability 1 year after receiving a cochlear implant.