The Cotton osteotomy or opening wedge medial cuneiform osteotomy is a useful adjunctive flatfoot reconstructive procedure that is commonly performed; however, the outcomes are rarely reported owing to the adjunctive nature of the procedure. The Cotton procedure is relatively quick to perform and effectively corrects forefoot varus deformity after rearfoot fusion or osteotomy to achieve a rectus forefoot to rearfoot relationship. Proper patient selection is critical because the preoperative findings of medial column joint instability, concomitant hallux valgus deformity, or degenerative joint disease of the medial column might be better treated by arthrodesis of the naviculocuneiform or first tarsometatarsal joints. Procedure indications also include elevatus of the first ray, which can be a primary deformity in hallux limitus or an iatrogenic deformity after base wedge osteotomy for hallux valgus. We undertook an institutional review board-approved retrospective review of 32 consecutive patients (37 feet) who had undergone Cotton osteotomy as a part of flatfoot reconstruction. All but 1 case (2.7%) had radiographic evidence of graft incorporation at 10 weeks. No patient experienced graft shifting. Three complications (8.1%) were identified, including 2 cases with neuritis (5.4%) and 1 case of delayed union (2.7%) that healed with a bone stimulator at 6 months postoperatively. Meary's angle improved an average of 17.75 degrees , from -17.24 degrees +/- 8.00 degrees to 0.51 degrees +/- 3.81 degrees , and this change was statistically significant (p < .01). The present retrospective series highlights our experience with the use of the Cotton osteotomy as an adjunctive procedure in flatfoot reconstructive surgery.