This paper reviews published randomized trials in North America to determine whether minority groups are underrepresented in clinical trials of OCD. A search of the literature produced 40 randomized trials of both adults and children with OCD, conducted in the U.S. and Canada from 1989 to 2009 (N = 3777). The groups included in this review were Caucasians/European Americans, Black/African-Americans, Hispanic/Latino-Americans, Asian-Americans, Others, and Unknown. Of these, 22 of 40 trials reported ethnic/racial information or data was available by request. We focused on the 21 trials from 1995 to 2008 providing ethnic/racial information, and among those (N = 2221), 91.5% of participants were Caucasian, 1.3% were African-American, 1.0% were Hispanic, 1.6% were Asian, 1.5% were Other, and 3.1% were Unknown. We conclude that minorities are underrepresented in North American OCD trials. Therefore, it is not known if empirically validated treatments are effective for these groups. Recommendations for improving recruitment of minorities for future studies are discussed.