Reduction malarplasty for making an oval facial shape is popular in Asia. Surgeons generally prefer the intraoral approach to minimize the surgical incision and reduce the operation time between 2 approaches--intraoral and bicoronal approaches. However, fixation can be incomplete because of the narrow operation field, which can result in zygomatic nonunion on the fixation site through the action of the masseter muscle. In the past 5 years, 6 zygomatic nonunion patients who received reduction malarplasty through the intraoral approach visited our hospital with a limitation of mouth opening and a depression on the malar area. In every case, they were corrected by rib bone interpositional or onlay graft and miniplate refixation through a previous intraoral incision. During the follow-up period, the malar area depression was corrected in most cases. However, depression of the lateral orbital rim area remained in 1 patient. Mouth opening was almost normalized after postoperative mouth opening exercises. Zygomatic nonunion after reduction malarplasty is a serious complication that is very difficult to correct. Deep understanding of the anatomy of the malar complex and the action of the masseter muscle and careful consideration of fixation during surgery is essential in reduction malarplasty.