The psychometric properties of the revised Breast-Feeding Attrition Prediction Tool, based on the Theory of Planned Behavior, were examined in this study. The sample consisted of 201 postpartum women who planned to breast-feel at least 8 weeks. Four scales identified by factor analysis measured the three TPB constructs. All scales sbowed moderate internal consistency (alphas .79 to .85). Two scales distinguished between women with and without prior breast-feeding experience (p <.05). Three scales were significantly related to breast-feeding attrition at 8 weeks. Women who weaned prematurely received less breast-feeding support from their social and professional network, believed breast-feeding was difficult, and saw more advantages to formula feeding than to breast-feeding. A discriminant analysis of the scales correctly identified 73% of the women who weaned prematurely.