This study was designed to evaluate the influence of Sesamum indicum extract on the mechanical properties of two formulations of glass ionomer cement. Material and Methods: A total of 90 samples of glass ionomer cement were prepared according to the test type. The samples were divided into 2 equal groups (n=45) according to the type of glass ionomer cement; Group (1): Conventional Glass ionomer cement, Group (2): Experimental Glass ionomer cement. Each group was further subdivided into 3 subgroups (n=15) according to the ratio of Sesame oil, subgroup (A): Glass ionomer cement without Sesame oil, subgroup (B): Glass ionomer cement with Sesame oil ratio1(v/v%), subgroup (C): Glass ionomer cement with Sesame oil ratio 4(v/v%). All the samples were submitted to evaluate the following properties, compressive strength, diametral tensile strength, and shear bond strength. Results: GICs modified with 1(v/v%) Sesame oil exhibited a significant increase in their compressive strength but a significant decrease in diametral tensile strength and a non-significant decrease in shear bond strength. GICs modified with 4(v/v%) Sesame oil exhibited a significant decrease in compressive strength, and diametral tensile strength, while a non-significant decrease in shear bond strength. Conventional glass ionomer cement exhibited significantly higher compressive strength than the experimental one but was not significantly lower in diametral tensile strength and shear bond strength. Conclusions: Sesame oil enhanced the compressive strength at low concentration with no significant effect on shear bond strength, while it showed a weakening effect on compressive strength at high concentration and determinal effect on tensile strength at both concentration for both glass ionomer cement formulations