Objective: The objective of this study was to synthesise and describe adherence to intervention in published studies of supported self-care for depression or anxiety, and to identify participant characteristics associated with higher adherence. Methods: We searched the databases EMBASE, MEDLINE, CINAHL, and PSYCINFO for the period from January 1986 until September 2010. Eligible studies reporting on adherence to supported self-care interventions for depression or anxiety symptoms were identified. Results: We identified 40 studies of supported self-care interventions for depression and anxiety, of which 22 (55%) reported any measure of adherence to the intervention. Among these 22 studies, 18 (82%) reported the percentage of participants completing the entire self-care tool (20%-93%; Mean = 66%, SD 17), 13 studies reported the amount of self-care tools completed by the average participant (50.6%-96.4%; Mean = 80%, SD 11.6). Four studies (18%) reported the frequency of contacts with the self-care guide. Three (14%) studies reported participant characteristics associated with adherence. Conclusion: Overall, reported adherence levels to supported self-care interventions for depression and anxiety indicate a significant amount of patient involvement in these interventions. Routine reporting of adherence will improve our understanding of adherence to supported self-care interventions, and will allow researchers to link adherence with intervention outcome.