A new internal fixation device was applied to 41 proximal tibial osteotomies to ensure against loss of postoperative correction. An oblique osteotomy was stabilized by two screws and a five-hole one-half tubular plate. Thirty-six patients with 41 proximal tibial osteotomies were reviewed for an average roentgenographic follow-up time of 22.6 months (range, six to 48 months) with no loss of correction. In addition, 16 patients with 19 osteotomies and a minimum clinical follow-up time of two years were reviewed using the Hospital for Special Surgery knee scoring system; these early results demonstrated a similar outcome to previously published series. The new fixation device is simple to use, permits early postoperative motion, and maintains the exact correction obtained at the time of surgery.