Improvements in adjuvant systemic therapy and detection of early disease have resulted in a decline of breast cancer death rates across all patient age groups in Canada. Non-adherence to adjuvant hormonal therapy in the setting of early breast cancer may significantly affect patient outcome. Factors associated with medication adherence are complex and may be patient-related, therapy-related, and health care providerârelated. To date, there is a gap in the literature concerning a comprehensive understanding of factors related to medication adherence with anti-estrogen therapy in the adjuvant setting. The literature suggests that strategies for improving adherence should focus on education of patients, assessment of the ability of patients to understand their disease and related recurrence factors, and facilitation of adherence by patients by providing adequate support and strategies for good self-management. However, more research is needed to better understand how health care providers can support women with breast cancer on oral therapy in the adjuvant setting.