A negative correlation between mathematics performance and mathematics anxiety (MA) has been identified in students of varying ages. However, little is known as to whether this correlation diminishes when environmental factors are incorporated as moderator variables. Specifically, the effect of home numeracy activities (HNA) and parental MA on students’ performance-MA relationship has received little attention. Furthermore, there have been no studies that consider HNA frequency as reported by the children themselves. A sample of 311 Chilean second graders and their parents participated in the present study. We examined whether HNA frequency moderates the performance-MA relationship and whether this moderation is in turn moderated by parent MA. Results showed that the frequency of HNA strengthened or diminished the negative correlation between performance and MA as a function of parent MA. In the case of parents with low MA, regardless of HNA frequency, child mathematics performance was negatively associated with child MA. However, in the case of math-anxious parents that interacted frequently with their children, there was no association between child MA and math achievement. More broadly, the present study suggests that mathematics-related family dynamics and parents’ emotions are key to understanding the relationship between performance and MA in early development.