Background:We estimated the Vitamin C content and antibacterial effect of citrus fruits on oral bacteria. Material and methods: The following citrus fruits were used: lemon, wild lime, gooseberry, pomegranate, Averrhoa bilimbi, orange and mosambi. The extracts of these citrus fruits were tested against the following bacterial strains: Streptococcus viridians, Staphylococcus aureus and Moraxella catarrhalis. The estimation of Vitamin C content in different citrus fruits was done by carrying out titration experiments against standardised 2, 4-indophenol dichlorophenol dye. The Antibacterial effect was determined using Kirby-Bauer's disc diffusion technique. Results: The wild lime extract showed the highest antibacterial property, while pomegranate extract showed the least antibacterial property towards all the three strains of bacteria tested. Streptococcus viridians was the most sensitive bacteria against all the citrus fruits extract. The zone of inhibition produced by undiluted lemon extract and vitamin c tablets was similar against all the three of bacteria. Conclusion: We conclude that citrus fruit extract have antibacterial properties against some common bacterial strains in the oral cavity.