Background: A woman’s prior breastfeeding history may influence future decisions regarding infant feeding. Few quantitative tools utilizing this information have been demonstrated to predict breastfeeding success. Research aim: To evaluate the efficacy of a prenatal breastfeeding history (BAP) questionnaire administered in prenatal care to predict in-hospital formula supplementation among multiparous women. Methods: This is a prospective observational study of multiparous women with singleton pregnancies who presented to a Baby-Friendly urban tertiary care center for 1st prenatal visit at < 20 weeks’ gestation. The BAP tool generates a numerical score, with higher score (≥ 2) indicating prior successful breastfeeding experiences. The primary outcome was occurrence of non-medically indicated formula supplementation during the postpartum hospital stay. Student’s t test and Pearson’s chi-square test were used to compare continuous and categorical variables. A multivariable logistic regression was performed to assess the relationship of BAP score to formula supplementation. Of 587 women screened, 433 (73.8%) mother–infant dyads were analyzed. Results: Rates of formula supplementation in women with BAP scores ≤ 1 were 67% (156/234) compared with 37% (73/199) in women with higher scores ( p < 0.0001). After controlling for race/ethnicity, insurance, and obesity, women with BAP scores of ≤ 1 were 2.6 times more likely to supplement formula than women with higher scores (a OR 2.62, 95% CI [1.70, 4.04], p < .0001). Conclusion: In this prospective validation study, women with negative prior breastfeeding experiences, as evidenced by a lower BAP score, were more likely to supplement formula during the postpartum hospital stay.