Clinical practice must be based on evidence. When evidence suggests that a certain practice may be ineffective or even harmful, that practice should be discontinued. The Choosing Wisely campaign, an initiative of the ABIM (American Board of Internal Medicine) Foundation, is intended to bring attention to tradition-based practices, or “sacred cows,” which lack evidence to support their ongoing use. The complex process of discontinuing or reducing the use of tradition-based practices is known as “de-implementation.” Recognizing the importance of de-implementation is necessary to fully understand evidence-based practice. This article explores the de-implementation process, examining its barriers and facilitators. Three critical care exemplars of tradition-based practices are presented and examined through the lens of de-implementation. Barriers and facilitators related to de-implementing these tradition-based practices are described, with an emphasis on the roles of various stakeholders and the need to overcome cognitive dissonance and psychological bias.