Background: Dental caries is a major concern to the dentist. Many bacterial subspecies are associated with caries, but Streptococcus mutans is still the most important bacterium in the initiation and progress of this disease. the direction toward natural products for medicinal purposes has gained much attention, as these natural products have proven to be effective with less toxic side effects. Studies have also shown other important properties in propolis such as antibacterial, antifungal, antiviral, anti-inflammatory, anesthetic, and ability to promote healing. Objective: To study the effect of propolis ethanolic extract (EEP) on enhancing the antimicrobial activity of glass ionomer cement (GIC). Methods: Two EEP 25% & 50% concentrations were evaluated for antimicrobial activity, in combination with GIC using agar Disk Diffusion test and broth microdilution test. Results: The diameter of the inhibition zone increased with 25% EEP & 50% EEP over the control by 14.4% and 19.6%, respectively. While increasing the concentration from 25% to 50% resulted in only 5% increase in the inhibition zone. MIC calculation for the three groups revealed, the combination of GIC and EEP has reduced the mic against Streptococcus mutans by two folds. Conclusion: The addition of propolis in different concentrations to GIC increased the antibacterial effect. 25% EEP gave the best antibacterial action with the lowest concentration.