<p>Mathematics anxiety and mathematical engagement are influencing factors on the mathematical achievement of students. In this study, self-report questionnaires from 409 students from three compulsory education schools in Mainland China were used to quantitatively investigate their mathematics anxiety, mathematical engagement and mathematics performance, and their relationships were explored. The factors representing the mediating effect of mathematical engagement include behavioural, emotional, cognitive and social aspects.</p><p>The results of the descriptive statistics, <i>t</i> test, correlation analysis and mediation analysis reveal the following: (1) students’ mathematical engagement is high, their anxiety is low, and their academic performance is good; (2) the higher the grade level of a student, the greater the level of mathematics anxiety and the lower their level of engagement; (3) female students have significantly higher social engagement than male students; (4) anxiety is negatively correlated with engagement and performance, whereas engagement is positively correlated with performance; and (5) the direct effect of mathematics anxiety on performance is not significant after controlling for mathematical engagement. The indirect effect of mathematics anxiety on performance via behavioural engagement and cognitive engagement is significant; conversely, emotional engagement and social engagement do not have this effect. The findings offer possible reasons and potential effective teaching strategies for compulsory-stage mathematical educators, which can help them improve their students’ mathematics performance from multiple perspectives.</p>