Objective The Accreditation Council for Graduate Medical Education (ACGME) requires that pediatric residents demonstrate competence administering immunizations. Despite mandatory simulation training, less than half our residents reported immunization competence. All residents need to receive their influenza vaccination, but schedule restrictions present logistical challenges. We implemented a peer influenza immunization workshop and assessed the impact on resident immunization competence compared to simulation-only training. Methods Prospective cohort study at a pediatric residency program in a tertiary academic center. We implemented an annual influenza immunization workshop including immunization education, simulated practice, and peer influenza immunization. We compared workshop participation to simulation-only training on resident confidence immunizing, number of immunizations logged, and ACGME survey results for immunization skills. Results In 2019, 80% (N = 59) of residents participated in the workshop. Participants were more likely to report confidence in immunization skills than nonparticipants (P = .001). Resident-administered immunizations increased from 1 in the 3 years preceding workshop implementation to 74 during the 2019 to 2020 academic year. Significantly, more ACGME survey respondents reported preparedness to immunize after workshop implementation (P = .02). Conclusions Implementation of an influenza immunization workshop provides an innovative opportunity to increase resident preparedness performing an ACGME-required procedure while also helping ensure programs remain compliant with influenza requirements.