Background: Promoting breast milk expression and cup feeding supports maternal and child health by reducing dependence on formulas, thereby minimizing associated health risks and financial costs. Objective(s): This study aims to evaluate the effectiveness of a nursing education program on breast milk expression and infant cup feeding among pregnant women. Methods: A quasi-experimental pre/post-test design study was conducted in two maternal and child health centers with 422 pregnant women. The study utilized an interview questionnaire assessing personal data, knowledge of breast milk expression and storage, and an observational checklist for expression steps and cup feeding. The educational program was developed based on a comprehensive literature review and delivered through group sessions (12–14 participants per session) using videos, printed handouts, and structured practical demonstrations with researcher-designed breast and infant models and sterile storage bottles. Immediate post-intervention assessment was performed to evaluate improvement in participants’ knowledge and reported practices. Results: Nearly half (46.9%) of participants were aged 25-35 years. Before the intervention, only 29.4% of the pregnant women were aware that breast milk can be stored, 1.9% knew the correct duration for storage at room temperature, and 4.0% were able to correctly label and store expressed milk. Practical skills were also lacking, with just 4.2% using the correct expression technique, 6.2% practicing proper hygiene, and only 4.5% tracking daily milk intake. Post-intervention, the total knowledge score significantly improved from 10.18 ± 5.14 to 19.11 ± 3.11 (p < 0.001). The mean score for breast milk expression steps increased from 3.35 ± 1.92 to 7.12 ± 1.42 (p < 0.001), while cup feeding practice scores rose from 3.92 ± 2.75 to 5.34 ± 1.08 (p < 0.001). Conclusion: The study highlights a significant improvement in the knowledge and practice of breast milk expression and cup feeding among pregnant women following the intervention. The total knowledge score, as well as the practice scores for expressing breast milk and cup feeding, showed a statistically significant increase post-test. Keywords: Breast milk expression, Cup feeding, Pregnant women