Aim and objective: To evaluate the effect of different herbal extracts such as Azadirachta indica, Morinda citrifolia, and green tea on the microhardness of radicular dentin and compare the effects of these herbal extracts with 2.5% sodium hypochlorite and saline. Materials and methods: In all selected 60 single-rooted, human permanent teeth, standardized access opening and working length determination were done. Later, instrumented to the apical size of 30 (F3) with ProTaper universal using saline. Each tooth was sectioned longitudinally using a low-speed diamond disc into two halves. Then, one-half without any defects was selected and embedded horizontally in auto-polymerizing acrylic resin, by exposing their dentin. The dentine surfaces on either side of the root canal lumen of these mounted specimens were flattened and smoothened with series of ascending grades of silicon carbide abrasive paper and finally polished with a composite polishing kit and 0.1-mm alumina suspension on a rotary felt disk. Then, all teeth were divided into five groups (n = 12) group I: saline, group II: 2.5% sodium hypochlorite, group III: A. indica, group IV: M. citrifolia, and group V: green tea, based on final irrigant. Initial and posttreatment microhardness was recorded using Vickers microhardness tester at coronal, middle, and apical third. Results: Group II and group IV showed statistical significance (p < 0.05) between initial and posttreatment values, while group I, group III, and group V, had no significance (p > 0.05). In comparison between group II and group IV, no significant difference was seen. Conclusion: Among herbal extracts, M. citrifolia leads to structural changes in radicular dentin due to demineralizing effect on root canal dentin.