Monocephalus tripus tribrachius, a type of conjoined twins with one head and three upper and lower extremities, is a rare congenital disorder. To date, no long-term follow-up results of surgical procedures for this condition have been reported in Korean literature. We experienced a case of monocephalus tripus tribrachius, which had been surgically managed with an accessory lower limb disarticulation and pelvic bone reconstruction to manage this accessory limb and accompanying comorbidities in hip joint and pelvis. Subsequently, ipsilateral Syme amputation was done for intractable deformity of foot, and later, ipsilateral femoral varus derotational osteotomy was done for inadequate coverage of femoral head observed in follow-up. We report 18-year follow-up results of the procedures with a review of literatures.