There are studies especially at higher education level investigating the subsequent responses of students towards reciprocity, tacit agreement and assessment of peers, but research on the effect of gender on peer assessment is limited. The present study focuses on whether peer assessment used in cooperative learning groups varies with respect to gender and investigates the compatibility level of peer assessments with teacher grades. This study was conducted in a primary school fourth grade social sciences course with 46 participants, 28 female and 18 male, their ages ranging from 9 to 10. The study rendered different results of peer assessment, where male and female students scored their fellow and opposite sexes with respect to their contribution to group work and their learning levels. The compatibility between female and teacher scores was higher than male and teacher scores. (Contains 2 tables.)