Introduction: The diagnosis of pure neural leprosy (PNL) remains difficult due to absence of characteristic skin lesions. Prior to the advent of invasive nerve biopsy, patients with pure neural leprosy were mainly diagnosed based on clinical judgement. Nerve biopsy and polymerase chain reaction (PCR) based tests are increasingly being done to diagnose PNL. Aim: To assess and compare the diagnostic value of nerve biopsy and RLEP3 gene detection using polymerase chain reaction tests in suspected cases of pure neural leprosy. Material and methodology: The study is a prospective non-randomised analytical study done for a period of 12 months in a tertiary care hospital in Chennai. Clinically suspected patients having pure neural leprosy with a sample size of 30 patients were included in the study. After clinical evaluation, basic investigations, nerve conduction study and slit skin smear for AFB, nerve biopsy and polymerase chain reaction assay were performed. Results: Specific histopathological findings were obtained in 3 out of 30 cases with 66.67% sensitivity, 40.74% specificity and 53.7% accuracy rate. PCR was positive in 7 out of 30 cases with 100% sensitivity, 52.17% specificity and 76.08% accuracy rate. In this study PCR was positive in additional 4 cases in which nerve biopsy was negative. This affirms PCR as an indispensable tool & necessity of using PCR in AFB negative cases. Conclusion: PCR based assay is more sensitive than nerve histopathology in the diagnosis of pure neural leprosy. A multimodal approach comprising clinical evaluation, nerve biopsy and PCR based assay gives the maximal diagnostic yield in suspected cases of pure neural leprosy.