The incidence rate of breast cancer is increasing and has become the most common cancer in Vietnamese women while the survival rate is lower than that of developed countries. Early detection to improve breast cancer survival as well as reducing risk factors remains the cornerstone of breast cancer control according to the World Health Organization (WHO). This study aims to evaluate the costs and outcomes of introducing a mammography screening program for Vietnamese women aged 45-64 years, compared to the current situation of no screening. Decision analytical modeling using Markov chain analysis was used to estimate costs and health outcomes over a lifetime horizon. Model inputs were derived from published literature and the results were reported as incremental cost-effectiveness ratios (ICERs) and/or incremental net monetary benefits (INMBs). One-way sensitivity analyses and probabilistic sensitivity analyses were performed to assess parameter uncertainty. The ICER per life year gained of the first round of mammography screening was US$3647.06 and US$4405.44 for women aged 50-54 years and 55-59 years, respectively. In probabilistic sensitivity analyses, mammography screening in the 50-54 age group and the 55-59 age group were cost-effective in 100% of cases at a threshold of three times the Vietnamese Gross Domestic Product (GDP) i.e., US$6332.70. However, less than 50% of the cases in the 60-64 age group and 0% of the cases in the 45-49 age group were cost effective at the WHO threshold. The ICERs were sensitive to the discount rate, mammography sensitivity, and transition probability from remission to distant recurrence in stage II for all age groups. From the healthcare payer viewpoint, offering the first round of mammography screening to Vietnamese women aged 50-59 years should be considered, with the given threshold of three times the Vietnamese GDP per capita.