Whether to continue or discontinue warfarin before fecal occult blood testing (FOBT) requires comparison of the risks and benefits of both choices. Clinical practice varies on this issue, and guidelines are silent. A small body of evidence about the effect of warfarin on test characteristics of FOBT is inconclusive, although it suggests no effect. Retrospective studies on this topic may be prone to transfer bias, which affects the composition of the groups assembled for study. Considering the risks and benefits of discontinuing warfarin qualitatively, along with the published literature and clinical context in 2010, where tolerance for false-positive results is higher than it used to be and where immunochemical FOBT is a better screening test than older, guaiac-based FOBT, "no" seems like the "commonsense" answer.