African Americans show unusually high endorsement rates on self-report measures of contamination anxiety. The purpose of this study was to replicate this finding in a nationally representative sample and conduct a randomized experiment to determine the effect of salience of race as a causal factor. Black and White participants were given contamination items from two popular measures of obsessive-compulsive disorder, half prior to being primed about ethnic identity and half after being primed, via the administration of an ethnic identity measure. The experiment took the form of a 2 (Black and White participant) X 2 (ethnicity salient and ethnicity non-salient) double-blind design, with ethnic saliency assigned at random by computer. Participants consisted of a geographically representative US sample of African Americans supplemented with a similar sample of European Americans (N=258). Black participants scored significantly higher than White participants on contamination scales. Participants from Southern states scored higher than those from other regions. Over-endorsements by Black participants were greater when awareness of ethnic and racial identification was increased. Clinical and research implications were discussed; these measures should be used with caution in African Americans.