<![CDATA[Bacterial contamination in pharmaceutical products, food, cosmetics, and the environment is a health problem that can cause various adverse impacts on the community. Lack of knowledge about the sources, dangers, and ways to prevent bacterial contamination is one of the factors that increase the risk of health problems. This community service activity aims to increase the knowledge and awareness of students at SMA Swasta Muhammadiyah 3 Medan regarding the dangers of bacterial contamination and the importance of implementing clean and healthy living behaviors. The activity involved 19 participants with a one-group pretest-posttest design, including counseling, demonstrations through educational media, and discussions and questions and answers held on June 5, 2026. Knowledge measurement was carried out using a questionnaire with 10 multiple-choice questions before and after the presentation of the material. The results of the activity showed a decrease in the number of participants in the category of less than 6 to 2 people, while the category of very good increased from 4 to 8 participants, and the category of perfect increased from 2 to 6 participants. The increase in the proportion of participants in the very good and perfect categories, accompanied by a decrease in the proportion of the less than 6 category, indicates an improvement in participants' understanding after participating in the activity. Participants also appeared enthusiastic and active in the discussion session. Thus, this community service activity effectively increased students' knowledge and awareness of the dangers of bacterial contamination and encouraged the adoption of clean and healthy living behaviors in their daily lives.]]>
