This study investigates the Differential Item Functioning (DIF) of the West African Examinations Council (WAEC) mathematics test based on gender and age among secondary school students. Mathematics proficiency is crucial for individual success and national development, yet disparities in test performance persist. Utilizing a quantitative approach, a stratified random sample of 50 students who took the WAEC mathematics test was analyzed. The study aimed to identify the presence and extent of DIF, analyze its impact on test scores, explore potential causes, and propose recommendations. Results indicate slight performance differences between genders and significant variances across age groups. While some test items exhibited bias favoring specific genders or age ranges, the magnitude of DIF indices was relatively small. Recommendations include regular item review, inclusive test design, advanced statistical analysis, educator training, policy reforms, student support, and further research. Implementing these recommendations can foster fairer and more valid educational assessments, ensuring equitable opportunities for all students.