Background: The present study was conducted to compare the efficacy of PUI system with CNI system in smear removal. Materials & Methods: 60 single‑rooted mandibular premolars were divided into 3 groups of 20 each. Group I teeth were irrigated with conventional needle irrigation (CNI) system and group II teeth were irrigated with passive ultrasonic irrigation (PUI) system and group III had negative control. The remaining smear layer was analyzed using SEM. Results: The mean smear layer score was significantly less in CNI group as compared to PUI and control group (P< 0.05). Conclusion: Conventional needle irrigation was found to be better as compared to passive ultrasonic irrigation in smear layer removal. Key words: Conventional needle irrigation, Passive ultrasonic irrigation, Smear layer.