Adherence to prescribed medication is important to the management of all diseases, especially those of chronic nature. Drug effectiveness is substantially compromised by therapy nonadherence. We reviewed the available evidences on the impact of patient preferences for therapy on adherence to a prescribed treatment in chronic diseases requiring long-term treatment. A search on PubMed retrieved 699 publications, leading to a selection of 12 publications: 6 on osteoporosis, 2 on moderate-to-severe asthma, 1 on type 1 diabetes, 1 on type 2 diabetes, 1 on kidney transplantation, and 1 on atrial fibrillation. Overall, 8 studies found a positive association between patient preference and adherence to therapy, while the others found no association. In general, overall adherence was considered to be high in the published studies. The reasons for a positive association included reduced dosing frequency, route of administration, lower costs, and favorable safety profile, which is related to the diverse nature of the pathology and its type and duration of treatment. A literature review suggests that achieving good adherence and persistence to therapy requires evaluation of patient preferences. In a period of increasingly limited resources, more effort is warranted to promote better adherence to therapy, especially when patients must self-manage their disease in the long term. Our results further highlight that insufficient attention has been given to the relationship between patient preference and adherence and point out the complex nature of adherence and the need for adequate patient education. More efforts are also needed to better understand the entity of cost savings for payers for specific treatments and the link with patient preference.