The early use of fluoride dentifrice and use of larger quantities recently have been identified as risk factors for dental fluorosis. However, little is known about fluoride dentifrice use and ingestion among infants and young children whose developing permanent teeth are at risk for dental fluorosis. This paper reports on patterns of fluoride dentifrice use among a birth cohort up to 12 months of age as reported by mothers by written questionnaire. Among those with teeth, percentages whose teeth were brushed at age 6, 9, and 12 months were 12.9%, 36.7%, and 64.5%, respectively. Percentages brushing with fluoride dentifrice were 1.9%, 11.7%, and 31.7%. Among those using dentifrice, the percentages using fluoride dentifrice were 94-97%. Among those using dentifrice, mean estimated quantities of fluoride from dentifrice used per brushing were 0.11, 0.14, and 0.17 mg F (range up to 0.88 mg). Among users, mean quantities of fluoride from dentifrice used per day were 0.21, 0.20, and 0.19 mg F (range up to 1.75 mg). Results suggest that fluoride dentifrice use among infants varies greatly, can be substantial, and can be a risk factor for dental, fluorosis.