Previous research suggests that direct pharmacist involvement with patients via medication reconciliation, discharge counseling, and postdischarge phone calls reduces adverse drug events (ADEs) and improves transitional care. Pharmacist engagement in transitional care has been studied, but not with many postdischarge calls. This study examined how pharmacist involvement in transitions of care affected medication errors (MEs) and ADEs, patients' medication communication knowledge (HCAHPS score improvement), and 30-day all-cause inpatient readmissions and ED visits. This prospective, randomized, single-period longitudinal research was conducted in an urban, tertiary, academic medical facility from November 2012 to June 2013. Randomization included patients hospitalized to 2 designated internal medicine units on high-risk drugs or with more than 3 prescriptions at release. The control group got hospital treatment as normal. The research group received face-to-face medication reconciliation, a patient-specific pharmaceutical care plan, discharge counseling, and postdischarge phone calls on days 3, 14, and 30 to educate and evaluate study outcomes. The final analysis comprised 278 patients—141 control and 137 trial. Fifty-five control patients (39%) had an inpatient readmission or ED visit within 30 days after release, compared to 34 study patients (24.8%) (P 5 0.01). In the control group, 18 patients (12.8%) had ADEs or MEs, compared to 11 (8%) in the study group (P > 0.05). The questionnaire domain HCAHPS scores improved 9% throughout the trial (P > 0.05). Pharmacist engagement in hospital discharge transitions of care reduced composite inpatient readmissions and ED visits, according to one research. Medication-related incidents and HCAHPS ratings did not vary statistically. Pharmacy teams helped moderately difficult patients transfer between care. Hospital Medicine 2016;11:39–44. VC 2015 Hospital Medicine Society