Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused many complications, the invention of coronavirus disease 2019 (Covid-19) vaccines has also brought about several adverse events, from common side effects to unexpected and rare ones. Common vaccine-related adverse reactions manifest locally or systematically following any vaccine, including Covid-19 vaccines. Certain side effects, known as adverse events of special interest (AESI), are unusual and need more evaluation. Here, we discuss some of the most important rare adverse events of Covid-19 vaccines.