The hypothesis that deficits of children with Down syndrome on working memory tasks are more evident the higher the control required and for verbal than visuospatial tasks was tested. Two groups of children, one with Down syndrome, who ranged in age from 7 to 18, and a control group were assessed with batteries of verbal and visuospatial working memory tests requiring different levels of control. On tasks requiring low control, children with Down syndrome showed impairment of verbal but not visuospatial working memory tasks. As the requirement for control increased, they showed greater impairment on both tasks. Children with Down syndrome were comparatively better in visuospatial than verbal tasks. Implications of these results for working memory models and the role of working memory in intelligence were discussed.