Context: According to the previous studies, general anesthesia infl uences the Immune System. Evaluating such impacts on the Immune System helps to improve the management of anesthesia. Evidence Acquisition: The current review aimed to summarize the literature related to the eff ects of general anesthesia agents on the cytokines. Google Scholar, PubMed, and ISI/Web of Sciences databases were searched using the following keywords: cytokine, general anesthesia, Immune response, intravenous anesthetics, volatile anesthetics, opioids, benzodiazepines, and controlled ventilation. Results: Long-term administration of general anesthesia drugs, due to their eff ects on cytokines, can lead to disease progression in patients with Immune defi ciency. Due to the confl icting results of various studies and the increasing number of patients with Immune defi ciency, the choice of the appropriate general anesthesia agents facilitates achieving the more favorable function of the cytokines. Conclusions: It seems that the eff ect of general anesthesia on the Immune System in healthy patients and short-term surgeries is not considerable and changes in the Immune System are related to surgical trauma, particularly in major surgery.