The present study was conducted on 374 (188 females and 186 males) randomlyrnselected high school students. The major purpose was to investigate the genderrndifferences of 9th and 11th graders in mathematics achievement as a function of mathrnself-efficacy and math anxiety.rnTo do this, mean difference tests and path analyses model were employed.rnAccordingly, in the four high school random samples of 9th and 11til grade boys and girlsrnstudied, the boys scored significantly higher than the girls did in math self-efficacy andrnin math achievement tests. The girls were significantly more anxious about math thanrnthe boys. However, no gender difference was found in math anxiety for 11th graders.rnThe mean difference tests further suggest students with high math self-efficacy and lowrnmath anxiety scores were superior in their math achievement than those with low mathrnself-efficacy and high math anxiety level. In addition, the correlational analyses indicaternthat math anxiety adversely affect the math self-efficacy and math achievement of highrnschool students (grades 9 & 11). Thus, it is concluded that high school students whornthat they lack the confidence to do mathematical problems develop negative affect tornthe subject, which in turn results in negative attitude that culminates in poor mathrnperformance.rnThe path analyses model for the pooled subjects, except grade level, the otherrnvariables had revealed a statistically significant direct effect on math achievement. Mathrnself-efficacy had strong direct and total effect on math achievement followed by mathrnanxiety. Math self-efficacy had a mediational and predictive role in the academic arena.rnRegarding the gender sub-group path analyses model, for both genders math selfefficacyrnand math anxiety had statistically significant direct effects on mathrnachievement, the predicting power being higher for males than females. For the pooledrnas well as the gender sub-group, the contribution of math self-efficacy to achievementrnwas higher than the other variables considered in the study.