Aim: The aim of the study was to investigate the incidence and configuration of C-shaped root canals in mandibular second molars in North Indian population using clinical and radiographic method and to compare the relative efficacies of these two methods. Methods and Material: 500 patients with mandibular second molar teeth scheduled for root canal treatment over a period of 1.5 years were examined during 2018-2019. C-shaped root canals were determined by clinical examination using modified Melton's criteria and by radiographic method using Fan’s criteria. Results: Incidence of C-shaped root canals was found to be 6.80% using clinical method and 5.20% using radiographic method. Females had greater (9.4%) predilection than males (4.69%) clinically. There were only 19 teeth in which presence of C-shaped root canal were confirmed both clinically and radiographically. Aim: The aim of the study was to investigate the incidence and configuration of C-shaped root canals in mandibular second molars in North Indian population using clinical and radiographic method and to compare the relative efficacies of these two methods. Methods and Material: 500 patients with mandibular second molar teeth scheduled for root canal treatment over a period of 1.5 years were examined during 2018-2019. C-shaped root canals were determined by clinical examination using modified Melton's criteria and by radiographic method using Fan’s criteria. Results: Incidence of C-shaped root canals was found to be 6.80% using clinical method and 5.20% using radiographic method. Females had greater (9.4%) predilection than males (4.69%) clinically. There were only 19 teeth in which presence of C-shaped root canal were confirmed both clinically and radiographically.