To reduce immune rejection and maintain normal function of the kidneys, patients with transplanted renal need immunosuppressive agents, such as cyclosporine, tacrolimus, and sirolimus for the long term. These drugs directly influence cell metabolism and facilitate the proliferation of fibroblasts, thereby leading to drug-induced gingival overgrowth. Patients with low immunity are vulnerable to pathogens, are more likely to develop plaque deposits, and have gingivitis or periodontitis. As for oral mucous, these patients are susceptible to infections of Candida albicans or herpes simplex virus and have diseases like hairy leukoplakia, fissured tongue, lip cancer, and ulcers. One year after renal transplantation, higher prevalence of caries is observed, which may be related to low salivary Immunoglobulin A levels caused by immunosuppressive agents. Patients(30.43% of the total) have jaw deformities, which may also be related to immunosuppressive agents. These oral diseases not only affect oral functions, such as mastication, pronunciation, and esthetic appearance, but also cause severe systemic diseases like diabetes mellitus, cardiovascular diseases, and digestive tract diseases. Knowing the relationship between renal transplants and oral diseases and choosing an appropriate medication could help reduce drug-related side effects, decrease the prevalence of oral or other systematic diseases, and improve the quality of life of renal transplant patients.