Objective: The discovery of vaccines during the COVID-19 pandemic was encouraged to establish immunity and decrease the effects of the virus. Vaccines, like any other medicine, include the possibility of side effects. This study was carried out to categorize the side effects and to show that no severe side effects developed. In this study, we aimed to examine the patients who came to the emergency department with side effects after administering the inactivated vaccine. Material Methods: In this study, between January and March 2021, healthcare workers and people over 80 who applied to the emergency department after developing a side effect after administering the Coronavirus disease-2019 (COVID-19) vaccine were included. Results: In the study, 82 (82.8%) were healthcare professionals, and 17 (17.2%) were in the over-80 age group. The most common side effect was COVID-like findings (47.5%). While the rate of applications to the emergency department after the first dose of vaccination was69.7% (n=69), it was observed that it decreased to 30.3% (n=30) after the second dose of the vaccine. Conclusion: In general, post-vaccination side effects are tolerable and not life-threatening. Furthermore, the risk of becoming infected with the virus post-vaccination is lower. Therefore, hesitation to vaccinate may cause more risk.