Case Study: Since the declaration of the 2020 COVID-19 pandemic, large-scale vaccinations are being carried out worldwide to prevent infection and progression to severe disease. Among them, SARS-CoV-2 mRNA vaccine is known to prevent COVID-19 infection by making antigens activating T cells and B cells. Here, we report the case of minimal change disease (MCD) with nephrotic syndrome and acute kidney injury after vaccination with Moderna's vaccine (mRNA-127) in a 34-year-old male patient without underlying disease. He had periocular edema from the day after vaccination, and he visited the emergency room due to generalized edema along with dyspnea. There was a weight gain of 2 kg for 3 days after vaccination and had edema in both legs, abdomen, and scrotum. He had not taken any new drugs recently, and had no upper respiratory tract infection. He denied drinking alcohol and smoking cigarettes. At the time of admission, serum creatinine level was 0.86 mg/dL, albumin level was 1.4 g/dL, and 24-hour urine protein excretion was 7.7 g/day. A kidney biopsy was performed and the findings were consistent with MCD. From the the 4th day of hospitalization, the renal function began to decrease, and the creatinine level rose to 5.38 mg/dlL. Eleven weeks after initiation of high dose prednisolone therapy, serum creatinine level was 0.90 mg/dL, albumin level was 3.7 g/dL, and spot urine protein-to-creatinine decreased to 0.14 g/g. In this case, it is unclear whether vaccination affected the first onset of MCD or whether the timing of vaccination and onset of MCD coincidentally overlapped. Additional reports and continuous research on kidney-related side effects that occur after vaccination are needed.