The objective of this study is to know the influence of religious/spiritual elements on the adherence to pharmacological therapy. The descriptors used for this literature review were "medicine, medication, drug, or treatment," "adherence to treatment," and "religion or spirituality or faith or prayer" in different databases (CINAHL, PsycINFO, PubMed). Finally, 23 articles were selected. Articles available in full text, published between 2010 and 2017, in English or Spanish were included. The results showed that some studies relate positively the R/S and therapeutic adherence, but others determine an opposite or even mixed effect, mainly addressing pathologies such as HIV and other chronic diseases. The influence of religiosity/spirituality on therapeutic adherence requires that health professionals acquire sensitivity and competence to address these issues with their patients.