Adverse drug reactions (ADRs) are common, yet are often underreported making them difficult to track and study. Prospective pharmacovigilance programs significantly increase detection and reporting of ADRs. The aim of this pilot study was to apply triggers used by a prospective pharmacovigilance program at a free-standing children's hospital to retrospectively detect ADRs at our institution, therefore determining if these methods could be replicated and provide the basis for implementation of a prospective pharmacovigilance program. In 2019, our institution had 22,000 inpatient admissions and 51,000 emergency room visits and had 21 ADRs voluntarily reported in an electronic medication safety tracking system. Additional ADRs were identified by methods including new or modifications to the patient's allergy profile in the electronic medical record (EMR) and International Classification of Disease (ICD) codes. We identified 754 unique patients with changes to allergy profile and 5,719 ICD codes in 3,966 unique patients to evaluate. These triggers prompted screening of the EMR to validate the ADR, and we identified 280 ADRs occurring in 2019. Eight (2.8%) were identified solely by the electronic medication safety tracking system, 64 (23%) were identified by the allergy list, 110 (39%) were identified only by ICD coding, and the remaining 98 (35%) were identified by multiple methods. The use of triggers followed by review of the EMR identified thirteen-fold more ADRs than were voluntarily reported, illustrating the need for an active pharmacovigilance service and the successful use of multi-modal methods to detect and track ADRs. This article is protected by copyright. All rights reserved