This paper is motivated by a desire to advance assessment in the health professions through encouraging the judicious and productive use of metaphors. Through five specific examples (pixels, driving lesson/test, jury deliberations, signal processing, and assessment as a toolbox), we interrogate how metaphors are being used in assessment to consider what value they add to understanding and implementation of assessment practices. By unpacking these metaphors in action, we probe each metaphor's rationale and function, the gains each metaphor makes, and explore the unintended meanings they may carry. In summarizing common uses of metaphors, we elucidate how there may be both advantages and/or disadvantages. Metaphors can play important roles in simplifying, complexifying, communicating, translating, encouraging reflection, and convincing. They may be powerfully rhetorical, leading to intended consequences, actions, and other pragmatic outcomes. Although metaphors can be extremely helpful, they do not constitute thorough critique, justified evidence or argumentation. We argue that although metaphors have utility, they must be carefully considered if they are to serve assessment needs in intended ways. We should pay attention to how metaphors may be misinterpreted, what they ignore or unintentionally signal, and perhaps mitigate against this with anticipated corrections or nuanced qualifications. Failure to do so may lead to implementing practices that miss underlying and relevant complexities for assessment science and practice. Using metaphors requires careful attention with respect to their role, contributions, benefits and limitations. We highlight the value that comes from critiquing metaphors, and demonstrate the care required to ensure their continued utility.