Under the Lanham Act and the Trademark Revision Act of 1988, trademarks may be cancelled if it is ruled that consumers use the brand name to describe a generic category. Trademark cancellation, or “genericide,” has high stakes in that it can result in the loss of a valuable corporate asset. The authors provide an overview of the history of trademark cancellation cases and examine what types of evidence are considered in such cases. The authors provide an analysis of trends in recent court rulings and advice for avoiding genericide.