Objectives: This research was performed in an attempt to develop an experimental endodontic material based on siwak oil to be tested according to American dental association (ADA) for the feasibility of its use as an endodontic sealer. Materials and methods: In this study, a commercially available zinc oxide –based endodontic sealer served as a control. For the experimental endodontic material, extracted arak (siwak) oil was mixed with zinc oxide powder of the control sealer. Initially, the siwak oil was extracted from the dried roots of siwak by consecutive ethanolic soaking method. Prior to testing the experimental sealer, the powder/liquid ratio was determined using the documented one inch string method to attain an ample consistency suitable for clinical use. Some physical properties of the experimental endodontic material based on siwak oil were evaluated according to ADA specification No.57 for endodontic sealers .The evaluated properties were working time, setting time ,flow ,film thickness, and dimensional stability .Finally, the evaluated properties were compared to the gold standard sealer; Zinc oxide eugenol sealer .The data were collected ,tabulated and statistically analyzed.Results: Zinc oxide –siwak material exhibited significantly shorter working time and setting time as well as thinner film thickness than those of zinc oxide-eugenol control sealer. Regarding the flow and the dimensional stability % values, both materials showed non-significant difference.Conclusions: The consistency of the experimental Zinc oxide/siwak oil paste proposed physical properties relevant to an endodontic sealer. The experimental sealer was submitted to ADA spevification No.57 and its properties are promising. The reduced working and setting times suggested easier manipulation and better clinical performance than those of the gold standard sealer .The comparable flow and the significantly reduced film thickness of the experimental sealer are potential characteristics for improved sealing quality. Siwak oil extract sealer could be added satisfactorily to the recent classification of dental cements under the category of oil based cements which contains only Zinc oxide eugenol cement.