Maxillary sinus augmentation is a procedure commonly performed in patients in need of maxillary posterior implants with loss of vertical ridge height and sinus pneumatization. Previous studies have identified some factors associated with sinus membrane perforation during lateral-wall sinus elevation procedures. Although membrane perforation does not directly link to future implant failure, it has been shown to have an association with postoperative complications. In order to promote more predictable results and reduce complications during the sinus elevation procedure, especially for the lateral window approach, articles published in peer-reviewed journals were reviewed to support the proposal of a new risk-evaluation system prior to the sinus surgery. This article reviews anatomical and patient-related factors that might affect the risk of perforation during the surgery and also aims to provide a risk assessment table to enable clinicians to analyze these factors prior to the lateral sinus augmentation surgery.