Adequate knowledge of both external and internal radicular anatomy is a fundamental prerequisite for successful endodontic therapy. Maxillary premolar teeth present an endodontic challenge due to their increased prevalence for root and root canal aberrations. This review aims to discuss the occurrence of accessory roots and root canals in maxillary premolar teeth and its relation to different ethnic groups. A new classification is proposed to include all their accessory root and root canal configurations. In addition, the endodontic considerations, including their identification and management, are discussed. Keywords: accessory root, classification, maxillary premolar teeth, root canal