Background: Root canal treatment is performed to eradicate sources of irritation in the root canal and periapical tissues. The use of chemical agents during instrumentation to completely clean all aspects of the root canal system is central to successful endodontic treatment. Hence; the present study was conducted for assessing efficacy of two different root canal irrigating solutions. Materials & methods: A total of 45 freshly extracted mandibular first premolars were included. All the specimens were stored in normal saline. Coronal sectioning of all the specimens was done at the level of cement-enamel junction. Biomechanical preparation was done in all the samples. All the specimens were divided into three study groups as follows: Group 1: Physiologic saline, Group 2: 2.5% NaOCl, and Group 3: 10% citric acid followed by 2.5% NaOCl solution. After completion of biomechanical preparation, smear layer scoring was done (scanning electron microscopic evaluation) on a scale of 0 to 5 with 0 indicating no smear layer and 5 indicating heavy non-homogenous smear layer completely covering the root. Results: Mean smear layer score among specimens group A, Group B and Group C was 5, 4.12 and 2.39 respectively. Significant results were obtained while comparing the mean smear layer score among the specimens of the three study groups. Conclusion: From the above results, the authors concluded that 10% citric acid followed by 2.5% NaOCl solution had significantly higher efficacy in comparison to 2.5% NaOCl. Key words: Root canal irrigation, Root canal therapy