Aim: Mandibular first premolar shows frequent variations in root canal morphology which could influence the success of endodontic treatment. The aim of the present study was to assess the root canal morphological variations of mandibular first premolar teeth in Rajouri district population by decalcification and clearing technique. Methodology: Two hundred extracted mandibular first premolar teeth were collected from Rajouri district population. Decalcification and clearing procedures performed and then the teeth were assessed for tooth length, number of cusps and roots, number and shape of canal orifices and root canal configuration. Results: The mean length of mandibular first premolar teeth was found to be 20.8 mm. Majority of mandibular first premolar teeth were found to have single root followed by 2 roots. Root canal system of mandibular first premolars was found to be predominantly Type I followed by Type V. Conclusion: Mandibular first premolar teeth were mostly found to have one root and Type I root canal configuration.