Impairments in executive function have been documented in school-age children with mathematical learning difficulties. However, the utility and specificity of preschool executive function abilities in predicting later mathematical achievement are poorly understood. This study examined linkages between children's developing executive function abilities at age 4 and children's subsequent achievement in mathematics at age 6, 1 year after school entry. The study sample consisted of a regionally representative cohort of 104 children followed prospectively from ages 2 to 6 years. At age 4, children completed a battery of executive function tasks that assessed planning, set shifting, and inhibitory control. Teachers completed the preschool version of the Behavior Rating Inventory of Executive Function. Clinical and classroom measures of children's mathematical achievement were collected at age 6. Results showed that children's performance on set shifting, inhibitory control, and general executive behavior measures during the preschool period accounted for substantial variability in children's early mathematical achievement at school. These associations persisted even after individual differences in general cognitive ability and reading achievement were taken into account. Findings suggest that early measures of executive function may be useful in identifying children who may experience difficulties learning mathematical skills and concepts. They also suggest that the scaffolding of these executive skills could potentially be a useful additional component in early mathematics education.