This paper examines the role of Working Memory (WM) in developmental reading problems, considering: 1) The operationalization of WM; 2) The unique contribution of WM to reading; 3) Domain-general or -specific explanations of decoding and reading comprehension deficits; and 4) The capacity of WM constructs to distinguish between reading disabilities and attention-deficit/hyperactivity disorder (ADHD). It is concluded that: 1) Significant problems operationalizing working memory measures remain; 2) No clear unique role for WM is evident in longitudinal studies of reading acquisition; 3) Existing evidence concerning the domain-specificity or generality of WM problems is hard to interpret given problems in identification and sampling of poor readers and operationalization of WM constructs; 4) Further work is required to specify the nature of WM problems in samples of poor readers, as distinct from other co-occurring problems such as ADHD. Additional research is suggested to address these issues more fully.