Background: Recent single-center, retrospective reviews have evaluated the effect of influenza vaccinations on the incidence and severity of immune-related adverse events (irAEs) in patients receiving immune checkpoint inhibitors (ICI). Methods and outcomes in these studies vary. The most common medication investigated was ipilimumab, an Anti-CTLA-4 monoclonal antibody. There is limited data evaluating the incidence of irAEs in those receiving the specific ICIs, program death-1 (PD-1) and program death ligand-1 (PD-L1) inhibitors. Methods: A retrospective chart review was conducted including patients 18 to 89 years old who received single-agent pembrolizumab, nivolumab, atezolizumab, or durvalumab at an academic medical center from August 2015 to August 2019. The primary objective was to evaluate the incidence of irAEs in those who received an influenza vaccine compared to those who did not. Electronic health records, and the Louisiana Immunization Network for Kids (LINKS), which now collects adult information, were utilized for data collection. Chi-square tests were used to evaluate all endpoints. Results: Of the 217 charts screened, 133 were included in this study Fifty-three patients were included in the influenza vaccination group and 80 patients in the group that did not receive influenza vaccinations. The median age in those who received an influenza vaccine and in those who did not were 61 years and 62 years, respectively. The most common cancer diagnoses were lung cancer and melanoma. Ninety-one percent of patients in the vaccination group versus 81% in the group who did not receive an influenza vaccine received either nivolumab or pembrolizumab (PD-1 inhibitors). There was no statistical difference in irAEs in those who received an influenza vaccine versus those who did not (30% versus 45%, p = 0.15). The only significant secondary outcome found was the rate of irAEs in patients receiving a PD-1 inhibitor versus a PD-L1 inhibitor regardless of vaccination (42.2% versus 11.1%, p = 0.03). The majority of irAEs were grade 1 or 2. Conclusions: Based on this study, receiving an influenza vaccine does not have an influence on the risk of irAEs in those receiving ICI, specifically PD-1 and PD-L1 inhibitors. These outcomes may have been affected by adherence issues with yearly influenza vaccinations, inaccurate vaccine records, and receiving vaccines out of state. The statistically significant secondary outcome may have been affected by the disproportionate number of patients who were receiving a PD-1 inhibitor in this study. Larger population studies are needed to validate these findings and identify both the risk and benefit of patients receiving their yearly influenza vaccine while receiving ICI.