The authors present a case report of infantile nystagmus syndrome (INS) with abnormal head posture (AHP) of face turn, head tilt and chin depression with a single-step surgery of all four horizontal rectus muscles. The case was a 26-year-old male with a face turn of 30 degrees, tilt of 20 degrees and chin depression of 10 degrees. Binocular visual acuity improved with AHP. He was orthophoric with full ocular movements and positive binocular vision. Recession / resection surgery of all four horizontal rectus muscles was undertaken for the face turn, with full tendon width vertical transposition of these muscles for the head tilt. AHP improved postoperatively. He developed vertical diplopia postoperatively with a small right hypertropia of 6PD at distance and near fixation. He was given a prism and exercises for three months during which time the diplopia resolved. The authors provide a useful discussion of the amounts of surgery and reasons for moving specific muscles and direction of movements.