This cross-sectional study examines measles epidemiology and vaccine effectiveness in Al-Anbar Province, Iraq, analyzing 200 laboratory-confirmed cases from January 2023 to March 2024. The research reveals a concerning 71% breakthrough infection rate among vaccinated individuals, significantly exceeding WHO Eastern Mediterranean regional averages (45-50%). Key findings include high disease burden in infants and young children (32% under 12 months, 68% aged 1-9 years), severe complications including pneumonia (77%) and diarrhea (73%), and disproportionate rural impact (58%). Unvaccinated children showed 3.2-fold higher odds of pneumonia development. The study highlights critical immunization gaps and emphasizes the urgent need for enhanced surveillance, routine immunization strengthening, and comprehensive vaccine program evaluation to achieve WHO measles elimination goals in Iraq. Findings suggest region-specific challenges requiring targeted public health interventions.