Working mothers have a tendency not to exclusive breastfeeding. This study aims to assess the effectiveness of the Breastfeeding Education Package intervention on breastfeeding selfefficacy and exclusive breastfeeding for working mothers in Tanjungpinang. The study design was quasi-experimental in the form of a nonequivalent control group design. Working mothers who were at 28-34 weeks of gestation had allocated to intervention group and control group. The intervention in this study was a Breastfeeding Education Package as Breastfeeding Education Class during the prenatal period and breastfeeding counseling in the first week of postpartum, facilitated by AIMI Kepri. Thirty-three mothers completed the study, allocated to the intervention group (n=17) and control group (n=16). At the pretest measurement(p=0.996), 1-week post-partum (0.954) and ≥ 1-week return to work ( 0.200) didn’t show significant differences between groups. The practices of exclusive breastfeeding are also not a significant difference between groups (p=0.567), but the practice of exclusive breastfeeding is significantly higher for those who had a BSE score of ≥47,3 points (p=0.008).The difference in BSE scores between groups and at each measurement time was not significant but significant for the practice of exclusive breastfeeding based on BSE scores. Various efforts are needed to support the continuity of the breastfeeding process for working mothers

Breastfeeding Self-Efficacy, Working Mothers, Exclusive Breastfeeding, Breastfeeding Education, AIMI Kepri