Older adults in long-term care (LTC) are often frail and comorbid and have multiple medications. Although medication review by pharmacists has been integrated into LTC practice in many countries through policy and reimbursement models, the impact is variable in the literature. The purpose of our study was to review the literature regarding the impact of the pharmacist in LTC.Four databases were searched from inception to September 2017, including Ovid MEDLINE, Ovid Embase, Ovid Evidence-Based Medicine Reviews (Cochrane Library), and Ovid International Pharmaceutical Abstracts.Studies in any language were included if they met the following criteria: (1) pharmacist involved in care, (2) quasi-experimental or experimental design, and (3) conducted in LTC.Two reviewers independently reviewed the titles, abstracts, and full-text articles to determine if they met inclusion criteria, with a third researcher resolving discrepancies. Data of included studies were independently abstracted by 2 reviewers and confirmed by a third researcher.Twenty-six studies (total N = 20,228, median study duration = 12 months) met the inclusion criteria. Medication review was the most common intervention, evaluated in 24 studies (92%). Eleven studies (42%) reported on the total number of medications per patient, with 7 studies finding a statistically significant reduction in medication usage. Six studies focused on psychotropic medications, with 4 of those leading to a reduction in medication. Explicit medication appropriateness criteria showed improvement in 5 studies. Medication and health care costs were evaluated in 14 studies (54%), with 4 reporting a statistically significant reduction. Studies reporting hospitalizations (10, 38%) were moderately heterogeneous (I = 59%) and failed to demonstrate an impact. Studies reporting mortality (8, 31%) were less heterogeneous (I = 0%), but they also failed to show a change.There is evidence to support pharmacist intervention, primarily through medication review, to improve measures in medication appropriateness.