The goal of this study was to examine the relation between mathematics and working memory in young children with Fetal Alcohol Spectrum Disorders (FASD). Children with FASD and comparison children (4 to 6 years old) completed standardized tests of mathematics and working memory. Children with FASD showed impairments on mathematics (applied problems and quantitative concepts) as compared to comparison children. The FASD group also performed less well than the comparison group on measures of phonological working memory. Math performance was highly correlated with phonological working memory in both groups and with central executive working memory only in the FASD group. The mathematics deficits in children with FASD appear to be associated with underlying working memory impairments. (Contains 3 tables.)