Limited research has examined the skills of children with a reading disability (RD) and children with RD and a mathematics disability (MD). Even less research has examined the phonological awareness (PA) and rapid automatized naming (RAN) skills in these two groups of children and how these skills relate to reading and math achievement. Additionally, various classification criteria are frequently implemented to classify children with MD. The purpose of this study, therefore, was to examine the PA and RAN skills in children who met different criteria for RD only and children with RD who are at-risk for mathematics difficulties (MDR). Participants were 114 second or third grade students with RD from public elementary schools in three large metropolitan areas. Students were classified as at-risk for mathematics difficulties utilizing a 25th percentile cutoff and a 15th percentile cutoff as assessed by the KeyMath-Revised Test (Connolly, 1988). A series of PA and RAN measures were administered along with a range of reading and mathematics measures. Hierarchical regression analyses indicated that children with RD only evidenced a different pattern of results compared to children with RD + MDR. Additionally, using a more stringent criterion to classify children at-risk for mathematics difficulties resulted in a differential pattern of results when compared to a less stringent classification criterion.