There is a paucity of published literature on the injuries of the lesser toe sesamoids of the foot. A fifty-six-year-old male patient without a major trauma history was diagnosed as having a stress fracture of the fifth metatarsophalangeal joint medial sesamoid bone. Conservative treatment was employed and the patient was followed-up for 25 months without any complaints. The sesamoid bone injury of the fifth toe should be included in the differential diagnosis of lateral forefoot pain.