PURPOSE: assessment of the fracture resistance and microhardness of radicular dentine following irrigation with apple vinegar as a final rinse. MATERIAL AND METHODS: fifty extracted human lower premolars, in accordance to the inclusion criteria were chosen. All lower premolars were decoronated then prepared using M3 ProGold rotary files and irrigated with 2.6% NaOCl 2 ml/1 min. Then all samples were distributed randomly into 2 main experimental groups (20 samples each) depending on the final rinse. Group I: irrigated with Apple vinegar (AV), Group II: irrigated with 17% Ethylenediamine tetra acetic acid (EDTA) and a Control group (10 samples): irrigated with sterile saline. All samples were prepared to be subjected to either fracture resistance or microhardness tests. The universal testing machine was used to assess fracture resistance. While the Vickers microhardness test was used to determine microhardness. RESULTS: In terms of fracture resistance, the results revealed that group II (EDTA) had a statistically significant reduction in fracture resistance, compared to group I (Apple vinegar), as well as the control group (saline). However, there was no statistically significant difference between group I (Apple vinegar) and control group (saline). While there was no statistically significant difference in total microhardness between the two main experimental groups, there was a statistically significant reduction in microhardness in the experimental groups as compared to the control group. CONCLUSIONS: Regarding fracture resistance, apple vinegar shows better results than 17% EDTA. While, it is comparable to 17%EDTA in microhardness of radicular dentine.