Statins are the most powerful lipid lowering drugs in clinical practice. However, the efficacy of statin therapy, as seen in randomized control trials, is undermined by the documented non-adherence observed in clinical practice. Understanding the clinical consequences of statin non-adherence is an important step in implementing successful interventions aimed at improving adherence. Our previous systematic review included a literature search up to January 2010 on the effects of statin non-adherence or discontinuation on cardiovascular (CV) and cerebrovascular outcomes. We provide an update to this publication and a review of promising interventions that have reported a demonstrated improvement in statin adherence. Through a systematic literature search of PubMed, Ovid Medline, Ovid Embase, CINAHL, Cochrane Library and Web of Science, out of the 3440 initially identified, 13 studies were selected. Non-adherence in a primary prevention population was associated with a graded increase in CV risk. Individuals taking statins for secondary prevention were at particular risk when taking statin with highly variable adherence. Moreover, particular attention is warranted for non-adherence in diabetic and rheumatoid arthritis populations, as non-adherence is significantly associated with CV risk as early as 1 month following discontinuation. Statin adherence, therefore, represents an important modifiable risk factor. Numerous interventions to improve adherence have shown promise, including copayment reduction, automatic reminders, mail-order pharmacies, counseling with a health professional, and fixed-dose combination therapy. Given the complexity of causes underlying statin non-adherence, successful strategies will likely need to be tailored to each patient.