Approximately two-thirds of patients discharged from an emergency department (ED) are prescribed at least one medication. Prescription clarification by outpatient pharmacies for ED patients can lead to delays for patients and added workload. This study aims to describe prescriptions requiring clarification prior to being dispensed by an outpatient pharmacy for patients recently discharged from an ED. This study was conducted at an urban, 61-bed academic ED. Prescription clarification forms were used to identify common causes for outpatient pharmacies to contact the ED to clarify prescriptions prior to dispensation. Clarification types were reviewed and classified. Descriptive statistics were used to present the classification types. There were 1278 documented calls to the ED for prescription clarification that were classified as clarification of directions for use (611, 47.7%), insurance or affordability issues (182, 14.2%), dose (172, 13.4%), medication availability (126, 9.8%), lost or missing prescription (93, 7.3%), patient allergy or adverse event (62, 4.8%), duplication in therapy (17, 1.3%), and clarification of medication ordered (17, 1.3%). When grouped into provider, system, or patient-related issues, provider issues were noted to be most frequent clarifications (862 clarifications, 67.3%), followed by system issues (325 clarifications, 25.4%), and finally, patient-related issues (93 clarifications, 7.3%). Clarification of directions for use, insurance or affordability issues, and clarification of the dose were the most common reasons that outpatient pharmacies contacted an ED regarding a prescription for a recently discharged patient.