Osteotomy is a good method for correcting a metatarsus varus and a hallux valgus if the first metatarsophalangeal joint has little or no arthritis, no luxation and is mobile. Osteotomy of the neck of the first metatarsal is recommended when the articular surface of the first metatarsophalangeal joint has a certain lateral obliquity. In these cases osteotomy of the base of the metatarsal, which exaggerates this obliquity, should be avoided. Osteotomy allows correction in all planes. As osteotomy of the diaphysis of the proximal phalanx is indicated in cases where the hallux is too long, is pronated, or if there is a phalanx valga. Internal fixation of these osteotomies with a lag screw has the advantage of maintaining the correction and allowing early mobilization. With the above-described technique, a physiologic as well as an aesthetic reconstruction may be obtained. The osteotomy must be performed very carefully in order to avoid the complications of recurrence of deformity, joint stiffness and pain.