Isolated rupture of the flexor hallucis longus tendon is an unusual injury. We present the case of a neglected flexor hallucis longus tendon closed traumatic rupture at the plantar aspect of the first phalangeal head of the great toe in a middle-age male. The injury occurred while he was dancing. Because end-to-end tendon suture was impossible, the ensuing gap was repaired using a free plantaris tendon graft. We present the operative repair benefit of the flexor hallucis longus tendon rupture to regain the function and strength of the interphalangeal joint of the hallux, avoid extension of the distal phalanx, and maintain the longitudinal arch of the foot.