This study investigated the effect of a health-related lifestyle on knowledge, attitude, control belief and behavior intention toward breast-feeding of male and female university students in order to develop a breast-feeding education program for students of childbearing age. The subjects were 445 university students (125 male and 325 female) residing in eight provinces in Korea. The overall percentage of subjects intending to breast-feed their baby was 80.7% (73.6% of males and 84.2% of females). Overall, 84.2% of the subjects had high concerns about their health status. Scores reflecting a positive attitude, knowledge, and control beliefs toward breast-feeding were significantly higher (p<0.05~p<0.001) in female students, students majoring in medicine, and higher grades. The students who scored high at attitude, knowledge, and control beliefs also had a significantly higher (p<0.001) intention to breast-feed. When we investigated the sub factors of attitudes toward breast-feeding, significantly more students taking nutrient supplements scored high for physiological factors (p<0.05) and health-related factors (p<0.01). Significantly more non-smoking and non-drinking students scored high for health-related factors (p<0.001) and physiological factors (p<0.001), respectively. The intention to breast-feed was found to be significantly higher (p<0.01) in students who did not smoke, but not with other health-related lifestyles. In summary, these results indicate that the majority of university students intend to breast-feed, with students having a positive attitude, higher knowledge, and stronger control beliefs having a higher intention to breast-feed. Although a student's health-related lifestyle affects their attitudes on the physiological and health-related aspects of breast-feeding, only smoking status had an observable connection on the intention to breast-feed. Thus, when developing breast-feeding education programs for students, we recommend efforts to enhance a favorable attitude, knowledge, and control beliefs toward breast-feeding.