Sinus augmentation, either osteotome or lateral window approach, is a predictable procedure to augment vertical height that allows for proper implant placement in areas with previous limited restorative options. Like any surgical procedures, there is always a risk of encountering either intrasurgical or postsurgical complications. A Medline literature search of articles published from 1984 to 2006 related to complications following sinus augmentation were selected and analyzed. To make it easier for understanding, sinus augmentation complications were classified into following categories: systemic disease and mediations related; anatomy and surgical procedure related; sinus pathology related; infection related; and prosthetic related. Depending on the source or cause of complication, treatment may include palliative approach to surgical intervention. This article will review a newly proposed complication classification, discuss treatment modalities for each encountered complication and propose methods to avoid these complications.