The C-shaped root canal configuration is one of the most important anatomic variations of the root canal system. It is commonly reported in mandibular second molars. The C-shaped canal configuration in maxillary first molars is rare, even more so, the presence in second maxillary molars has only been reported in one case report in the literature. This paper describes the presence of unusual bilateral C-shaped configuration in maxillary second molars. Palabras clave: anatomic variations, cone-beam computed tomography, diagnosis, root canal therapy, tooth abnormalities