© 2015. In 2015, inactivated quadrivalent influenza vaccine (QIV) was first introduced into the Australian market. A routine vaccine safety surveillance system in Western Australia was used to conduct post-licensure surveillance of adverse events following immunization with inactivated QIV and trivalent influenza vaccines (TIV) in a sample of 1685 healthcare providers (HCPs). A similar percentage of HCPs who received QIV reported having any reaction seven days post-vaccination as HCPs who received TIV (13.6 vs. 12.8%, respectively; p=. 0.66). However, a slightly higher percentage of HCPs who received QIV reported pain or swelling at the injection site as compared to HCPs who received TIV (6.9% vs. 4.2%, respectively; p=. 0.02). No serious vaccine-associated adverse events were detected during follow-up of either vaccine. Acknowledging the study limitations, the results of this post-marketing surveillance support the safety of QIV, suggesting there is little difference in the reactogenicity of QIV as compared to TIV.