The purpose of this study was to investigate the knowledge and attitude of a group of mothers who had infants about baby bottle tooth decay(BBTD) and dental caries prevention. The sample consisted of 261 mothers who had infants from 6 to 36 months from certain areas of Dae-jeon city. The mothers were asked to answer a questionnaire which included a series of questions regarding general information cencerning the infant and his mother, knowledge about BBTD and methods of prevention using fluoride, knowledge about behavioral risk factors contributing to caries of the infant, attitude toward oral health care of the infant, opinions regarding the effectiveness of methods to prevent dental caries and sources of oral health information. he results of this study were as follow. 1. 85.4% of the respondents thought that prolonged bottle feeding would harm the teeth of the infant, but 77% of the respondents had never heard of baby bottle tooth decay. 2. Levels of knowledge about methods of prevention using fluoride were relatively low and there were significant relationships between the levels of this knowledge and the educational level of the respondents(P<0.05). 3. Only 7.3% of the respondents thought that prolonged breast feeding would harm the teeth of the infant. 4. Overall oral health care of the infants was relatively insufficient. 5. Only 28.7% of the respondents selected either when the first tooth erupt or deciduous dentition complete as the time a infant should first be seen by a dentist. 6. 64.6% of the respondents thought that toothbrushing should be instituted once the first tooth appears. 7. Among the six methods of preventing caries in infants, respondents ranked the effective of fluoride lower than making regular dental visits and reducing intake of sugared foods. 8. Most frequently cited sources of information about dental health were newspapers, magazines and books(65%), followed by friends, neighborhoods and families (55%).