OBJECTIVES: To analyze the incremental cost-effectiveness ratio (ICER) of the rapid test for HIV ½ and Treponema Pallidum DPP® HIV-Syphilis Assay in pregnant women compared with current diagnostic methods. METHODS: Cost-effectiveness analysis was conducted using a double-stage decision tree with a 75-year time horizon for pregnant women and child, from the Mexican public health perspective. The model captures the sensitivity and specificity of each comparator as well as confirmatory tests in positive cases. Congenital transmission was captured according to time-to-treatment, which varies across comparators. Costs and effectiveness data were taken from public health institutions, extracted from published literature or provided by the developers of the rapid test. Final outcomes were measured in ICER per life year gained (LYG). Cost-effectiveness was determined according to the 1GDP/per capita threshold established by the National Health Council in Mexico. RESULTS: DPP® HIV-Syphilis Assay was dominant compared to all other treatments with a total cost of MX$23,395.11 over 75 years, and an effectiveness of 20.457 LYG. CONCLUSIONS: The present study identified that the dual rapid test for HIV ½ and Syphilis, with the name of DPP® HIV-Syphilis Assay and with a price of MX$105.00, is a cost-effective option for the early detection of HIV and Treponema Pallidum in pregnant women in the Mexican public health context.