Objective: Despite strong evidence that inattentive and hyperactive/impulsive behaviors are associated with mathematical difficulties in school-age children, little research has been conducted to examine the link between these constructs before the start of formal education. The purpose of this study was to examine how different manifestations of inattentive and hyperactive/impulsive behaviors, as measured by different assessment tools, are related to early mathematics skills in preschoolers. Method: Eighty-two preschool children completed a measure of early mathematics and the Continuous Performance Test (CPT). Teachers rated children's behaviors using the Conners' Teacher Rating Scale--15 Item. Sixty-five of these children completed mathematics assessments 1 year later. Results: Teacher ratings of inattention were uniquely related to concurrent early mathematics skills, whereas CPT errors were uniquely predictive of early mathematics skills 1 year later. Conclusion: Findings have implications for the understanding and assessment of behavior problems that are associated with early mathematics difficulties. [This article was published in "Journal of Attention Disorders," v20 n8 p704-714 Aug 2016.]