This qualitative study explored school-based HPV immunization in Mongolia following the 2023 amendment making HPV vaccination mandatory. Focus groups with 13 teachers from four regions revealed declining parental confidence in vaccines, misinformation, and logistical barriers, particularly in rural areas. Teachers highlighted challenges such as vaccine storage, transportation, and the need for clearer roles of school health staff. Findings emphasize the importance of collaboration between education and health sectors to ensure program success. Strengthening training and targeted communication is key to improving acceptance and coverage