Children with closed head injury (CHI) perform poorly on complex tasks requiring working memory (WM). It is unclear to what extent WM itself is compromised, and whether WM varies with factors related to the CHI, such as injury severity, age at injury, and time since injury. We studied verbal WM in 126 school-age children with CHI, divided into mild, moderate, and severe injury severity groups. WM distributions were significantly skewed toward lower scores in the moderate and severe groups, although the distribution in the mild group was normal. Age at injury and time since injury predicted WM components only for the moderate group. Survivors of moderate or severe childhood CHI have persisting WM deficits limiting the computational workspace required for many cognitive tasks.