A retrospective single-center cohort study was conducted on 35 patients with diffuse proliferative (WHO type IV) and/or membranous (type V) lupus nephritis (22 with type IV, 6 with type V, and 7 with type IV plus V) who had been treated with a sequential regimen comprising prednisolone and cyclophosphamide during active disease, followed by low-dose prednisolone and azathioprine maintenance. The follow-up period was 33.2 +/- 4.5 months. At presentation, 32 (91.4%) patients were nephrotic, and an abnormal serum creatinine level was noted in 14 (48.3%) patients with type IV changes. Cyclophosphamide was given for 26.8 +/- 2.8 weeks. 33 (94.3%) patients achieved complete or partial renal remissions: 77.3 and 22.7% of the type IV patients, 16.7 and 66.6% of the type V patients, and 14.3 and 71.4% of the type IV plus V patients, respectively (p < 0.0001 for type IV versus type V and for type IV versus type IV plus V). The duration of therapy before renal remissions and normalization of C3 were attained was similar among the three groups of patients. Disease relapse occurred in 4 (18.2%) of 22 IV patients and in 1 of the 5 type V patients in remission. Mortality was not observed, and none of the patients had an increase in serum creatinine level to double the baseline value. Adverse effects related to therapy included: hair loss (42.9%), transient amenorrhea (53.6%), leukopenia (11.4%), febrile episodes (14.3%), and herpes zoster(28.6%). We conclude that sequential use of prednisolone and cyclophosphamide followed by low-dose prednisolone and azathioprine can achieve favorable therapeutic results in the majority of patients with diffuse proliferative and/or membranous lupus nephritis, without excessive toxicities.