A series of specific clinical practice guidelines (CPGs) were published in Canada in 1998. A primary objective of these ‘Clinical Practice Guidelines for the Care and Treatment of Breast Cancer’ was to decrease the variation in breast cancer care across the country. Prior to this, researchers found moderate compliance with consensus recommendations for breast cancer therapies in several Canadian provinces. However, a recent study concluded that the publication of the Canadian CPGs did not reduce variations in surgical care for breast cancer. If guidelines are to achieve their intended objectives, they must be implemented in ways that support, encourage, and facilitate their use. Evidence strongly suggests the simple publication and passive dissemination of CPGs are usually ineffective in changing how physicians actually care for patients. CPG implementation, therefore, requires active knowledge translation processes to ensure that the evidence is relevant to all with a stake in bettering breast cancer care. For example, implementation strategies that use computerized CPGs can make evidence-based decision-making routine practice in the clinical setting. The breast cancer community can also work with the newly formed Canadian Partnership Against Cancer to find ways to more successfully support and facilitate guideline use considering the local context.