Early childhood caries is the most common chronic disease in young children and may develop as soon as teeth erupt. Bacteria, predominately mutans streptococci, metabolize simple sugars to produce acid that demineralizes teeth, resulting in cavities. Physicians should examine children's teeth for defects and cavities at every well-child visit. Any child with significant risk factors for caries (e.g., inadequate home dental care and poor oral hygiene, a mother with a high number of cavities, a high sugar intake, enamel defects, premature birth, special health care needs, low socioeconomic status) should be referred to a dentist by 12 months of age. Promoting appropriate use of topical and systemic fluoride and providing early oral hygiene instruction can help reduce caries in young patients, as can regularly counseling parents to limit their child's consumption of sugar.