Previous work has noted that math anxiety may have a profound effect on math performance; however extant research has relied on measures that explicitly assess math anxiety. This study examined the effects of implicit math anxiety on the performance of a math achievement task. We hypothesized that combined measure of implicit anxiety and explicit anxiety would better predict math achievement than measures of explicit math anxiety alone. In addition, we hypothesized that an individuals’ measured implicit anxiety and measured explicit anxiety would share only a modest correlation. To test these hypotheses, 175 participants completed measures of explicit anxiety, an implicit associations test designed to measure implicit anxiety, and a measure of math achievement. As expected, math achievement was better predicted when implicit anxiety was combined with explicit anxiety. Furthermore, scores on the implicit and explicit anxiety measures were not significantly correlated. These results suggest that implicit and explicit math anxiety are two distinct constructs, thus traditional methods for helping students deal with math anxiety may not be entirely successful if the implicit component is ignored.