The aim of this review is to present the case that working memory makes a vital contribution to problem solving. Following a brief introduction to working memory, links between working memory and cognitive tasks including problem solving are reviewed and illustrated. Next, relationships between mental representations of the problem (mental models) that are created in working memory and problem solving performance are described. Finally, applications of research for classroom practice is considered; this includes four main approaches to deal with the limit of working memory capacity to help students solve problems: to possess a large knowledge base, to decrease the information load in problem solving, to increase students" working memory capacity through specialized training programs, and to use representations