The objectives of present investigation were to formulate and evaluate herbal gel for mouth ulcer treatment of dried powdered guava leaves. Herbal gel was prepared by using different concentration of powdered guava leaves and Carbopol 934, Propylene glycol as a gel base. Formulations were evaluated for various parameters Infrared spectroscopy revealed that there was no interaction between powdered Guava leaves and Polymer. The formulated gel was transparent, homogeneous and pH ranges from 7 to 7.5. Formulation showed acceptable rheological behavior with applicable Spread ability and Extra debility properties. Anti-fungal studies of formulations showed excellent efficacy against Aspargiliousaureus, Candida albinos. From the experimental evidence of investor studies it was observed that powdered guava leaves contain flavonoids so it showed significant antioxidant effect. Developed herbal formulation was stable, safe and effective over to synthetic formulations for the treatment of mouth ulcer.