The study compares the achievement of Jewish and Arab students in the high school biology matriculation examinations in Israel with special reference to differences between boys and girls. While Jewish and Arab students follow the same syllabus and take identical matriculation examinations, significant differences exist in learning and achievement patterns. Major differences reported include: (1) girl:boy ratio of Jewish biology majors is 3:1 compared with 1:1 for the Arab biology majors; (2) Arab and Jewish girls achieve generally as well as boys; (3) Jewish students achieve better especially on tasks which require higher cognitive abilities; (4) Arab student have, on the average, more difficulty in handling multiple choice items; (5) the differences between Jewish and Arab students in paper and pencil tests are substantially larger than those obtained in practical laboratory tests; and (6) the gap between Jewish and Arab students appears to be closing especially in tasks which require either lower cognitive abilities or simple process laboratory skills. Possible reasons for the differences found and trends identified are discussed. (Author/ML)