Background: Clinical pharmacists have a vital role in intercepting prescribing errors (PEs) but their impact within a Jordanian hospital emergency department (ED) has never been studied. Objective: To evaluate the impact of clinical pharmacy services on PEs and assess predictors of physicians’ acceptance of clinical pharmacists’ interventions. Setting: This study was conducted in the ED of the largest governmental hospital in Jordan. Method: This was a pre-post study conducted in October and November 2019 using a disguised observational method. There were 2 phases: control phase (P0) with no clinical interventions, and active phase (P1) where clinical pharmacists prospectively intervened upon errors. The clinical significance of errors was determined by a multidisciplinary committee. The SPSS software version 24 was used for data analysis. Main Outcome Measure: PEs incidence, type, severity, and predictors for physicians’ acceptance. Results: Of 18003 patients, 8732 were included in P0