Milk can be considered as a non-cariogenic food. Milk dietary components were found to affect pellicle and plaque formation. Recently many milk derivatives and milk-like drinks have become popular as healthy foods. Objective: To investigate the effect of some milk drinks and tea on the formation of acquired pellicle and Streptococcus mutans adhesion. Methods: Premolar teeth obtained from orthodontic extraction with similar shape and size were used. Mixed stimulated whole saliva was obtained from 3 healthy volunteers. Tested solutions used in this study were whole milk, skim milk, corn milk, rice milk, sour milk, soybean milk and tea. Teeth were incubated in test solutions for 2.5 h, followed by saliva for 2.5h at 37°C. Specimens were washed twice with distilled water. Pellicle formed was collected in distilled water by sonication for 5min, and then subjected to SDS-PAGE analysis. The adhesion of S. mutans on pellicle coated teeth was observed under a scanning electron microscope. Results: The electrophoretic protein profiles of acquired pellicle formed after incubation with different milk solutions and tea differed. Acquired pellicle formed after incubation with tea showed less protein bands than with other incubations. Sour milk, corn milk, rice milk and soybean milk contained protein bands (MW 26, 27 and 23 Kda) which may affect bacterial adhesion on the tooth surface. The results from scanning electron microscopy also showed differences in bacterial adhesion. Conclusions: This data suggested that milk derivatives and milk-like drinks have different effects on acquired pellicle formation and bacterial adhesion. Supported by the Faculty of Dentistry, Mahidol University.