Objective: To know the distal caries in mandibular second molars due to impacted mandibular third molars and their association with the type of impaction of patients who visited a tertiary care dental centre in Lahore, Pakistan. Study Design: Cross-sectional study. Place and Duration of Study: 28 Military Dental Centre, Combined Military Hospital, Lahore Pakistan from Dec 2020 to Nov 2021. Methodology: The dental records of 378 patients reported at 28 Military Dental Centres were retrieved from the data bank,then decoded and analysed. Results: Out of 378 patients, 242(64%) males and 136(36%) females were referred to Oral and Maxillofacial clinics of 28 MDC to undergo surgical extraction of mandibular third molar teeth. Mesio-angular 242(64%), depth Class-B 281(74.3%), and Ramal relationship I 224(59.3) were the most common impactions referred for surgical removal. 289(76.5%) impactions of all categories were unilateral. 178(73.6%) mesioangular impactions had neighbouring second molar distal caries on Orthopentomogram while none of the transverse impactions had neighbouring second molar caries. A significant association between angulation of impaction and neighbouring second molar caries has been noted (p<0.001). Conclusion: Increased mandibular second molar distal caries were noted adjacent to Mesioangular, depth B, Class 1 Ramal relationship mandibular wisdom tooth impaction.Keywords: Distal caries, Mesioangular impaction, Orthopantomograms, Radiographic study, Surgical extraction.