This systematic review evaluates the evidence for verbal working memory (VWM) deficits in children with specific language impairment (SLI). Children with SLI show a marked deficit in receptive and expressive language with no known neurological, behavioral, vision or hearing impairments. The underlying causes of this disorder have been highly debated. Two conflicting theories have emerged. One proposes that the underlying cause of SLI is based in the absence of specific grammatical principles, and thus is purely a linguistic constraint. The second suggests that the surface language impairments are caused by underlying VWM deficits. Thirteen studies were included with a total of 263 participants previously diagnosed with SLI. This study showed that children with SLI show significant deficits in VWM in comparison with typically developing and language matched children. Children with SLI show VWM deficits that hinder their production and comprehension of language. VWM therapy practices should be incorporated into interventions when treating children with SLI. Research into specific intervention strategies is scarce, and a limitation in treating children with SLI.