Abstract: This study investigated the influence of cognitive styles and gender on upper basic III Mathematics students’ achievement in Keffi, Nasarawa State, Nigeria. The study was a descriptive survey research design. The population consisted of 1,890 upper basic III Mathematics students in 25 coeducational schools in the zone. The sample of the study comprised 245 upper basic III Mathematics students drawn from six intact classes of six coeducational schools in Keffi Education zone.