This study aimed to evaluate the psychometric properties of the Breastfeeding Self-Efficacy Scale-Short Form (BSES-SF) in Indonesian postpartum women. We conducted a cross-sectional study including 237 postpartum women in Yogyakarta City, Indonesia. Participants completed the BSES-SF, Edinburgh Postnatal Depression Scale (EPDS), and Hospital Anxiety and Depression Scale (HADS). Construct validity, internal reliability, and divergent validity were examined using confirmatory factor analysis, Cronbach’s alpha, and Pearson’s correlations. We identified a unidimensional structure through confirmatory factor analysis with an excellent internal consistency by Cronbach’s alpha of .90. Divergent validity was evidenced by low correlation of the BSES-SF with the depressive symptoms (EPDS, <i>r</i> = −.21; HADS-D, <i>r</i> = −.17, <i>p</i> < .05) and anxiety symptoms (HADS-A, <i>r</i> = −.15, <i>p</i> = .02). It is concluded that the Indonesian version of BSES-SF is a valid and reliable measurement tool to assess breastfeeding self-efficacy among postpartum women.