Transitions of care can contribute to medication errors and other adverse drug events.The aim of this study was to evaluate the impact of pharmacist-led discharge counseling on hospital readmission and emergency department visits through a systematic review and meta-analysis.Lectronic searches were performed in PubMed, Scopus, and DOAJ (Directory of Open Access Journals), along with a manual search (July 2017). PROSPERO registration no. CRD42017068444.Two independent reviewers performed all the steps of the systematic review process (screening of titles and abstracts, full-text appraisal, data extraction, and quality assessment), with contributions from a third researcher. We included randomized controlled trials (RCTs) reporting data on pharmacist-led discharge counseling.Primary extracted outcomes were emergency department visits and hospital readmission rates.Meta-analyses of intervention versus usual care for hospital readmission and emergency department visit rates were performed using the inverse variance method. Results are reported as risk ratios (RRs) with 95% confidence intervals (CIs). Prediction intervals (PIs) were also calculated. Sensitivity and subgroup analyses were performed. A total of 21 RCTs were included in the qualitative synthesis and 18 in the meta-analyses (n = 7,244 patients). The original meta-analysis revealed a significant difference in the impact between pharmacist-led discharge counseling and usual care on overall hospital readmission (RR = 0.864 [95% CI 0.763-0.997], P = .020) and emergency department (RR = 0.697 [95% CI 0.535-0.907], P = .007) visits. However, the small number of included studies, the high heterogeneity among trials (I2 between 40% and 60%), and the wide PIs (hospital readmission: PI 0.542-1.186; emergency department visits: PI 0.027-1.367) prevented drawing further conclusions.Insufficient evidence exists regarding the effect of pharmacist-led discharge counseling on hospital readmission and emergency department visits. Further well-designed clinical trials with defined core outcome sets are needed.