Background: The present study was conducted to assess the efficacy of PRP in Endo- Perio lesions. Materials & Methods: 58 patients with nonvital, immature premolars were treated with PRP. PRP fragments were placed into the canal space up to the CEJ. Root development was monitored by periapical radiograph. Results: Peri- apical healing was seen in 56 (96.5%) cases, apical closure in 44 (75.8%), root lengthening in 50 (86.2%) and dentinal wall lengthening in 48 (82.7%) cases. Conclusion: PRP is an effective way of treating Endo- Perio lesions. Key words: Apical closure, Endo- Perio lesions, Platelet rich plasma.