• Severe medial rectus injury occurred in two cases following intranasal sinus surgery. In the first case a scarred medial rectus muscle was found at the time of corrective surgery. Reexamination of the surgical specimen in the second case confirmed our finding of medial rectus transection. Both patients had good cosmetic and functional improvement by means of vertical recti transposition to correct their large angle, fixed exotropias. A review of the literature indicates that this is, to our knowledge, a previously unreported complication of intranasal sinus surgery.