The Streptococcus mutans is one of the main causes of pathologies such as caries. To generate its effects, S.mutans has several mechanisms, including adhesion between microorganisms and microorganisms in tooth enamel. Adhesins are surface or cell wall proteins of S. mutans fundamental to the adhesion process. Thus, blocking this type of protein could represent an inhibition or deceleration of the caries process. The Rosemary (R. officinalis L.) can promote several pharmacological effects due to the interaction between the molecules of the plant and the organic systems. The objective of this study was to verify the possible interaction between Rosemary and adhesion protein (antigen I / II) of S. mutans through molecular docking. First, we prepare the receptor (adhesin) by removing the heteroatoms using the UCSF Chimera. Then, we made several preparations in the receptor and in the ligand (Rosemary) using AutoDock Tools. Finally, the docking simulation took place in AutoDock Vina. The V-region of S. mutans antigen I/II (adhesin) and Alecrim connected with a free binding energy of -8.0 Kcal/mol. The molecules established 08 hydrogen bonds and 06 hydrophobic interactions. Considering the anti-microbial action of rosemary associated with its binding potential in adhesins demonstrated in the docking, Rosemary can be a potent aid in combating caries in dental products.