The aim of this study was to use SpiralCT to examine the root canal morphology of mandibular second molars in a South Indian population. One hundred and ten extracted mandibular second molars were scanned by Spiral CT scanner and analyzed for the number of roots, the number of root canals per root, and the root canal configuration in each root.The results showed that 91.91% of the molars had two roots, 4.55% had three roots, 5.45% had a single root, and only 0.91% had four roots. Three root canals were found in 62.73% of the teeth, followed by two canals in 20.02%. C-shaped canals were seen in 4.55% of teeth.In conclusion, the study found a predominance of two roots and three canals in the mandibular second molars of the South Indian population. Type IV canal configuration was common in mesial roots, and Type I in distal roots. The study also recorded the presence of three roots and C-shaped canals.