This study investigated, in children aged 6-13 years, how different components of the working memory (WM) system (short-term storage and executive processes), within both verbal and visuospatial domains, relate to fluid intelligence. We also examined the degree of domain-specificity of the WM components as well as the differentiation of storage and executive components. The short-term memory (STM) and WM tasks used allowed us to statistically separate the executive from the storage processes, enabling examination of separate processes in relation to intelligence. Our results demonstrated that all four WM components (verbal- and visuospatial short-term storage and verbal- and visuospatial executive processes) provided significant, independent contributions to intelligence, indicating that, in children, both storage and executive processes of the WM system are relevant to intelligence. Especially intriguing are our findings showing that verbal and visuospatial executive processes independently predicted intelligence, suggesting that, in children, the executive processes may rely on separate resources for the verbal and visuospatial domains. (Contains 2 tables.)