Prior research has suggested that mathematics specific anxiety and self-efficacy are strong predictors of mathematics performance. The purpose of this study was to examine this relationship using two nationally representative samples of Greek students in 2003 and 2012. Findings indicated that both mathematics anxiety and mathematics self-efficacy have showed a significant relationship with mathematics performance, and when these variables were incorporated in prediction models, as much as 34% of the total variation in mathematics performance was explained. However, socioeconomic status was the most potent predictor of mathematics literacy. Findings indicated the presence of a strong interaction effect between mathematics anxiety and mathematics self-efficacy. Educational implications and directions for future research are discussed.