Working memory enables us to hold a goal in mind while at the same time ignoring salient but irrelevant distractions; working memory capacity is instrumental to our ability to focus attention. The operation-span task, in which subjects try to remember several items while also carrying out arithmetic problems, is a widely used assay of working memory capacity; proficiency on this task has been found to correlate well with a wide array of other tasks that tap into top-down control of attention. However, attempts to correlate operation span with visual search performance have met with little success. We have previously shown that manipulating the salience of distractors' features can influence the relative contributions of bottom-up and top-down factors to attentional guidance in visual search tasks. By manipulating salience in this manner we were able to reveal a role for working memory in visual search.