Recognition of unusual variations in the root canal system is critical because it has been established that the root with a single tapering canal and apical foramen is the exception rather than the rule. C-shaped canal system is a variation that has a racial predilection and is commonly seen in mandibular second molars. The intricacies present in this variation of canal morphology can pose a challenge to the clinician during negotiation, debridement and obturation. The early recognition of these configurations facilitates cleaning, shaping, and obturation of the root canal system. "C" configuration, which is an important anatomic variation, presents a thin fin connecting the root canals. Knowledge of the C-shaped canal system is essential to achieve success in endodontic therapy. Radiographic and clinical diagnoses can aid in identification and negotiation of the fan shaped areas and intricacies of the C-shaped anatomy. The aim of this review is to discuss the etiology, incidence, classification, diagnosis and management of the C-shaped canal system.