This study compared the achievement of male and female students who were enrolled in an online univariate statistics course to students enrolled in a traditional face-to-face univariate statistics course. The subjects, 47 graduate students enrolled in univariate statistics classes at a public, comprehensive university, were randomly assigned to groups that used either online instruction or traditional face-to-face instruction. The effects of the independent variables of online univariate statistics instruction versus traditional face-to-face instruction on the dependent variable of statistics achievement were analyzed with a two-way analysis of variance. There was a significant difference between the achievement of students who used online univariate statistics instruction and those who used traditional face-to-face instruction (p = 0.001). The traditional face-to-face group scored higher with an effect size of 0.979, indicating that, on the average, those who were enrolled in a traditional face-to-face univariate statistics class outperformed 83.4% of those enrolled in the online statistics course. Moreover, females using online instruction outperformed males using online instruction and males enrolled in a traditional face-to-face course scored higher than females, with an effect size of 0.651, indicating that, on the average, those males outperformed 74.22% of the females enrolled in a traditional face-to-face statistics course.