Background: Evidence regarding the optimal dose of tacrolimus (TAC) in treatment of idiopathic membra- nous nephropathy (IMN) remains inconclusive. The ob- jective of this study was to evaluate the efficacy and safety of low-dose TAC combined with prednisone for patients with IMN. Methods: We conducted a randomized prospective cohort study in IMN patients: 28 patients received oral TAC (target whole blood concentration of 2-4 ng/mL) plus prednisone for 12 months, and 28 patients re- ceived prednisone combined with intravenous cyclo- phosphamide (CYC) (750 mg/m 2 body surface) once every 4 weeks for 24 weeks. Results: Of the 56 patients who completed the 12-month treatment, complete remission (CR) occurred in 8 (28.6%) of the CYC group and 18 (64.3%) of the TAC group; partial remission (PR) occurred in 10 (35.7%) of the CYC group and 7 (25.0%) of the TAC group. The probability of remission (either CR or PR) was higher in the TAC group than in the CYC group (p = 0.0439, by log-rank test). Furthermore, a significantly greater improvement in proteinuria and serum albumin levels was observed in the TAC group compared with the CYC group. Patients treated with TAC can often show a rapid increase in their serum albumin levels before any obvious reduction of urinary protein excretion. Side ef- fects were mild and transitory in both groups. Conclusion: The results demonstrated that the com- bined therapy of low-dose TAC and prednisone is an effective and safe therapeutic method for Chinese adults with IMN. Low-dose TAC accompanied by pred- nisone is enough to induce remission in the majority of patients with IMN.