Abstract
The purpose of the present study was to find out the gender differences in academic achievement of mainstream and religious school students. Sample of the study was 490 students of grade tenth. Average of the student's two terminal and a final examination achievement scores was calculated. In order to summarize the students' academic achievement scores, the descriptive statistics of mean and standard deviation were used. To find the significance of difference on achievement of male and female students, the t test was used. The level of confidence was decided as .05. It was found that the achievement scores of female students were higher as compared to male students from both categories of schools, meaning girls outperformed boys.