Background/Aims: Various treatment options for IgA nephropathy (IgAN) have been developed, particularly over the past decade. Nevertheless, whether such therapeutic interventions improve actual renal outcome as compared with previous therapies remains obscure. Methods: We examined data from 304 patients with IgAN whose serum creatinine value at renal biopsy was <2.0 mg/dl and who had been followed up for >12 months. We assigned the patients to groups according to the period of diagnosis (group E, between 1981 and 1995, n = 130; group L, between 1996 and 2006, n = 174). Results: Significantly more patients had received steroid therapy and renin-angiotensin system inhibitors (RAS-I) in group L than in group E (steroid 51.7 vs. 15.4%, p < 0.001; RAS-I 42.0 vs. 1.5%, p < 0.001). Forty patients overall reached end-stage renal disease (ESRD) within 81.9 ± 55.1 months of observation. Kaplan-Meier analysis showed that the 10-year renal survival rate of group L persisted and significantly differed from that of group E (95.7 vs. 75.2%, p = 0.005). The Cox proportional hazards model adjusted for known prognostic markers demonstrated that initial therapeutic interventions in group L prevented ESRD, with a hazard ratio of 0.29 (95% CI 0.11–0.76, p = 0.011). Conclusion: Although this study is not a prospective trial, our results indicate that aggressive therapeutic intervention for IgAN over the past decade has improved actual renal outcome.