The present paper offers a critical review of the current models of visuo-spatial working memory based on the analysis of individual differences. In the first part of the paper, the characteristics of the visuo-spatial working memory system, according to Baddeley (1986) and successive modifications of the model, are described. Then the paper considers the individual differences that have been shown to affect people's performance in visuospatial tasks related to the activity of working memory. In particular, the paper analyses the characteristics of visuospatial processing and working memory in children, the modifications occurring with aging, the differences related to gender and to the absence of visual perception due to congenital blindness. Altogether, the results indicate the amount of active specific processing as a variable greatly affecting people's performance in visuospatial tasks, thus leading to a theoretical distinction between passive storage and active processing in visuo-spatial working memory. The final discussion integrates these results to propose a modified version of the visuo-spatial working memory model.