During a urine drug testing program, an athlete may make a claim that the results of a positive test have arisen from factors that were out of his or her control, and therefore, he or she should not be held responsible for the results. Some of these claims may include classic claims of passive inhalation of marijuana smoke or ingestion of poppy seeds leading to positive tests. In addition, with the proliferation of nutritional supplements on the market, many athletes claim that they accidentally ingested a banned substance contained in one of these. It is important that any sports medicine physician involved with sports drug testing be informed of the data that either support or refute these claims and that he or she contribute to a program wherein adequate education and policy establishment help to limit the likelihood of such claims. This article will review the data to help address these claims.