One hundred and ten primiparas in the last trimester of pregnancy were divided into 2 equal groups of 55 each on the basis of their determination either to breast feed or bottle feed their infants. All subjects were administered a battery of projective tests and a comprehensive questionnaire prior to delivery, were seen in the hospital during the lying-in period, and were questioned in a follow-up survey from 6 weeks to several months post-partum. The following conclusions were drawn from the survey material. A significantly larger number of private patients succeeded in meeting the 6 weeks' criterion for successful breast feeding than did patients in the clinic population. While socioeconomic factors might partially account for this, the likelihood of success in the economically more privileged group is little better than chance. There was a mean of 11 nursing days for the total group reporting failure. Although first-year nursing students strongly favor breast feeding as the method of choice, both doctors and nurses on the house staff tend to express and act out negative attitudes toward breast feeding. Significant attitudinal differences exist between primiparas who choose to breast feed and those who reject this mode. Dominant attitudes of the bottle feeding group center around the wish for more freedom, convenience of bottle feeding, and narcissistic considerations. The breast feeding group was less swayed by these considerations (consciously) and stressed the feeling that the baby is happier with the breast. These expressed attitudes do not appear to sustain the intention to breast feed in a majority of the women. Extraneous influences play a minor role in the selection of a feeding choice, whereas emotional factors and unconscious motivations seem to predominate. It is suggested that the physician and the hospital accept the primipara's choice of feeding technique during the lying-in period and maintain a neutral policy.