Aims: The aim of the study was to assess whether maintenance of apical patency during instrumentation leads to altered postoperative pain in single-visit root canal treatment (RCT) as compared to non-maintenance of apical patency. Materials and methods: A total of 60 patients with symptomatic irreversible pulpitis in vital permanent mandibular molars were selected to be included in the study. The patients were randomly divided into two groups: group A, where apical patency was maintained and group B, where it was not maintained. The root canal procedures for the patients were carried out in single sitting under a rubber dam using E3 Azure (Endostar, Poland) rotary system, 2.5% sodium hypochlorite (NaOCl) as irrigant alternating with saline, and obturation by lateral compaction technique. A questionnaire employing visual analog scale (VAS) for pain assessment was given to the patient, and instructions on how to fill the form were given. The patients were recalled after 7 days, and the pain was analyzed. The result was tabulated and statistically analyzed. Results: There was no statistical difference in the postoperative pain between the groups where apical patency was maintained vs where apical patency was not maintained. Conclusion: Based on our findings and, in comparison with those of other studies, we conclude that there is no difference in postoperative pain when there is maintenance of apical patency vs non-maintenance of apical patency in permanent mandibular molars with vital pulps treated with single sitting root canals. Clinical significance: Achieving apical patency may not be mandatory for all cases of endodontics with respect to the goal of reduction in postoperative pain.