Aim: This in vitro study evaluated and compared the remineralizing potential of different herbal extracts aqueous solutions versus fluoride mouthwash by assessing the enamel surface microhardness and antimicrobial susceptibility.Materials and methods: Sixty extracted premolars were used in this study and equally distributed into six groups of 10 teeth each. Group A: teeth treated with 0.5% stevia aqueous solution; Group B: teeth treated 5% stevia aqueous solution; Group C: teeth treated with 0.5% green tea aqueous solution; Group D: teeth treated with 5% green tea aqueous solution; Group E: teeth treated with Fluoride mouthwash as a positive control group; negative control group: teeth not subjected to any treatment and stored in artificial saliva. The teeth of each group were subjected to microhardness assessment at baseline, after 48 hours demineralization, and after 7 days remineralization phase. The antibacterial activities of herbal extracts and fluoride against S. mutants and Lactobacillus were quantitatively measured by an antimicrobial susceptibility test. Results: After 7 days of treatment, the highest mean value was recorded in group D (282.69 Kgf/mm2) with the least mean value recorded in the control group (168.66 Kgf/mm2). The difference between groups was statistically significant (p= 0.001). The 5% green tea extract showed the highest mean value of inhibition zone (10.6 mm) against S. mutants' while fluoride showed the highest mean value of inhibition zone (14.6 mm) against the Lactobacillus. Conclusion: An aqueous solution of 5 % green tea is an effective remineralizing agent with antimicrobial activity against S. mutans.