In clinical practice, some IgA nephropathy (IgAN) patients show resistance to or are unable to achieve complete remission using steroids and/or immunosuppressants. The current study aimed to assess the efficacy and safety of tacrolimus in the treatment of cases of refractory IgAN.In this retrospective observational study, 34 primary IgAN patients with refractory proteinuria received tacrolimus for at least 12 months. Complete remission, partial remission, and other clinical data were measured at 1, 3, 6, and 12 months after the initiation of treatment.After 12 months, complete remission was achieved in 20 (58.8%) patients and partial remission in 5 (14.7%) patients, yielding a total response rate of 73.5%. The mean time for response to tacrolimus for those who achieved complete remission and partial remission was 7.04.7 weeks. Serum creatinine (Scr), uric acid, estimated glomerular filtration rate, alanine aminotransferase, aspartate transaminase, white blood cell count, blood pressure, blood glucose, total cholesterol, and total triglyceride were stable over time. Three patients demonstrated a loss of eGFR > 15mL/min1.73m(2) from baseline. Three cases of upper respiratory infection and 2 cases of urinary tract infection were observed during the study. Patients who achieved complete remission had better renal function and lower baseline proteinuria than partial remission and nonresponder patients. Crescent formation in biopsy specimens was seen more often in nonresponder patients.Tacrolimus was safe and effective at lowering proteinuria in refractory IgAN patients. Lower baseline proteinuria and better renal function were associated with a higher probability of complete remission, while crescent formation was associated with a worse prognosis.