Background: The present study compared EDTA and maleic acid on the surface microhardness of biodentine. Materials & Methods: 30 BD cylindrical‑shaped specimens were prepared and were divided into 3 groups of 10 each. In Group I, the specimens were treated with 17% EDTA, in Group II with 7% MA, in Group III with 5 mL distilled water as control. The surface microhardness of the specimens was measured using Knoop hardness tester. Results: There was significant difference in KHN in all groups. The mean KHN in group I was 78.2 KHN, in group II was 65.2 KHN and in group III was 126.3 KHN. Conclusion: Maleic acid resulted in maximum reduction in microhardness as compared to EDTA. Key words: bio dentine, Microhardness, Maleic acid