The aim of this study was to evaluate the in vitro activity of dentifrices containing the hydroalcoholic extract of the ripe fruit of Eugenia uniflora L. (Surinam cherry) on Streptococcus oralis (ATCC 10557) and Lactobacillus casei (ATCC 7469). Five dentifrices were used: D1: containing hydroalcoholic extract of Eugenia uniflora L.; D2: containing fluoride and hydroalcoholic extract of Eugenia uniflora L.; D3: containing triclosan and hydroalcoholic extract of Eugenia uniflora L; D4: containing triclosan, fluoride and hydroalcoholic extract of Eugenia uniflora L.; D5: positive control (Colgate Total 12). To determine the antibacterial activity, the technique used was the minimum inhibitory concentration by the diffusion method in solid culture medium. At the concentration 0.05 g/mL, the best results were achieved with D1 (18 mm) and D4 (24 mm) on L.casei, and with D3 (19 mm) on S. oralis. The dentifrices D3 and D4 were found to have greater activity on the Streptococcus oralis, while D4 and D1 were found to have greater activity on Lactobaccilus casei. It is concluded that dentifrices with Eugenia uniflora L. have antimicrobial activity, suggesting that clinical trials should be conducted.