The post operative iatrogenic hallux varus associates varus, big toe's dorsal flexion and supination. The pathogeny is dominated by musculo-tendinous lack of balance created by the initial operation and excessive exostosectomy. The authors have nineteen times surgically corrected this deformation. The procedure included in all cases, a medial arthrolysis; five times associated with a screwed capito-metatarsal osseous shelf (or graft) (when there was a metatarsal's head maiming); thirteen times associated with a metatarso-phalangeal arthrodesis (in cases of impaired joint surfaces). The authors analyse, besides, without excluding them the other surgical procedures for hallux varus, and particularly tendinous transfers. The results show the necessity of a perfect etiopathogenic analysis of the deformation.