Background:In order to increase affected tooth' life span, a successful endodontic treatment is required. Although mechanical preparation and proper irrigation play an important role in root canal treatment's success rate, yet application of intracanal medicament is still a major key in obtaining an endodontically favourable outcome. Objectives: to asses the change in dentin microhardness after the use of Nano-Propolis, Double Antibiotic Paste (DAP) and Triple Antibiotic Paste (TAP) as an intracanal medicament by Vickers Test. Materials and Methods: Forty-two extracted human single rooted lower premolars were collected and longitudinally sectioned in a bucco-lingual direction into two halves using a low-speed saw with a diamond disc. One half received the canal medicament while the other half was used as a control for dentin microhardness measurements. Teeth were divided into 3 different experimental groups equally according to the type of testing material; Propolis, Double and Triple Antibiotic Paste. Each group was further divided into 2 equal subgroups (7 each) according to the used medicament particle size either nano or micro sized. After two weeks, the difference between Propolis, DAP and TAP in nano and micro forms was investigated by Vicker's test to evaluate the micro-hardness. Results: A statistically significant difference was found in the median % reduction in radicular dentin microhardness. Conclusion:DAP, Nano TAP, Propolis, Nano DAP and TAP when used as intracanal medicaments adversely affects radicular dentin microhardness percentage reduction respectively, while Nano Propolis is considered safe as intracanal medicament regarding microhardness percentage reduction of root canal dentin.