© 2019, The Author(s). The body of research surrounding the relationship between visuospatial working memory (VSWM) and mathematics performance remains in its infancy. However, it is an area generating increasing interest as the performance of school leavers comes under constant scrutiny. In order to develop a coherent understanding of the literature to date, all available literature reporting on the relationship between VSWM and mathematics performance was included in a systematic, thematic analysis of effect sizes. Results show a significant influence of the use of a standardised mathematics measure, however, no influence of the type of VSWM or mathematics being assessed, on the effect sizes generated. Crucially, the overall effect size is positive, demonstrating a positive association between VSWM and mathematics performance. The greatest implications of the review are on researchers investigating the relationship between VSWM and mathematics performance. The review also highlights as yet under-researched areas with scope for future research.