Tacrolimus (FK506) is a novel macrolide antibiotic derived from the broth medium of soil fungi, which has a strong immune inhibitory effect, but its adverse reactions toxic side effects cannot be ignored. The side effects of tacrolimus may cause other clinical symptoms that directly or indirectly harm the patient. Under- standing the toxic side effects and adverse effects can provide valuable reference for clinical applications. The purpose of this article is to outline and summarize the potential side effects of tacrolimus toxicity, and briefly analyses the factors that lead to their creation. This work can provide a basis for clinical and follow-up studies.