The study examined the effects of gender and ethnicity on mathematics achievement on a national test and on dispositions (attitudes, perceived parental expectations, effort, and help) towards the study of mathematics of a representative sample of Jewish and Arab eighth graders in Israel. The results indicated a large ethnic gap in achievement in favor of the Jewish students. Significant gender-ethnicity interactions emerged whereby Arab girls, compared to Arab boys, attempted more items on the test. In the Jewish sample, either the reverse held true or there were no significant differences between the sexes. Arab girls also reported receiving less help in doing mathematics homework and perceived their parents' expectations for their success in mathematics as higher than did Arab boys. Jewish girls, on the other hand, perceived their parents' expectations as lower and reported investigating more effort in coping with mathematics tasks and using more supporting tools than did Jewish boys. The results were discussed in light of cultural differences between Jews and Arabs in Israeli society and their respective learning environments.