We evaluated the acceptability and effectiveness of atraumatic restorative treatment to prevent and treat caries in an underserved community in Mexico. We placed 370 restorations and 193 sealants in 118 children aged 5 to 18; 85% reported no pain, and 93% were comfortable with their restorations. We then evaluated the children 1 and 2 years later. At 2-year evaluation, 66% of restorations and 35% of sealants were retained. Atraumatic restorative treatment is acceptable and effective to control and prevent decay in a socioeconomically deprived community.