Visual attention is the collection of mechanisms by which relevant visual information is selected, and irrelevant visual information is ignored. Visual working memory is the mechanism by which relevant visual information is retained, and irrelevant information is suppressed. In addition to this overlap in definition, a strong overlap in brain areas active during attention and working memory tasks is found. The present paper reviews the behavioral evidence for and against the hypothesis that visual working memory and attention are best regarded as one and the same cognitive function, with the same capacity, the same control processes, and the same representational content. The data are best explained by a unified model in which multiple representations can be maintained, but only one receives the current focus of attention. Task circumstances then determine how successful this central representation can be prioritized over its mnemonic competitors.