Mathematics is one of the effective subjects in educational performance and prospective occupation. Gender differences in different academic disciplines, on the other hand, have been recently considered as the fitting foci of several research. This paper is empirically addressed gender differences in achievement in mathematics. To this end, 400 students (168 girls and 232 boy) were randomly sampled from Tehran, Iran high school. It is also to be mentioned that researcher used the math’ scores of final exam as a tool for evaluating achievement in mathematics. Data was analyzed through employing t-test. The results of the study manifested that there was a significant difference in the scores for boys (Mean= 14.58, SD= 3.46) and girls, (Mean=16.08, SD=3.22); t (373.95) = -4.45, p= .000 (two-tailed). Investigation of this kind leads to a better insight toward gender differences in several academic disciplines.
