Complexities of the root canal anatomy make it complex for dental practitioner to correctly diagnose. The c-shaped canal is one of the rare anatomic variation which is mostly seen in mandibular second molars because of the shape of the canal and root. A profound expertise of the tooth, root and root canal anatomy is essential for the success of the endodontic treatment. This case report presents a rare root canal system in a mandibular second molar tooth, a single root with a single canal. Shaped canals with varying configuration are commonly observed in single rooted mandibular second molars.