This study investigated whether measures of verbal working memory are less sensitive to children's socioeconomic background than traditional vocabulary measures. Participants were 120 school beginners, divided into high and low socioeconomic groups. The groups contained equal numbers of English first-language and second-language speakers. All were being educated in English. The results suggest that socioeconomic status accounts for considerable variance in vocabulary measures, while it explains only very small amounts of variance in working memory measures. In addition, the high socioeconomic group performed significantly better on the two vocabulary tests relative to the low socioeconomic group, while there were no significant differences between the groups on all but one of the four working memory tests. Working memory assessments appear to be less influenced by environmental factors and may constitute fairer forms of evaluation for children from differing socioeconomic backgrounds. As such, working memory measures may be a valuable supplement to psychoeducational assessment batteries.