BACKGROUND: Idiopathic nephrotic syndrome (NS) in children is classified as steroid sensitive or steroid resistant. Steroid sensitivity typically portends a low risk of permanent renal failure. However, some initially steroid-sensitive patients later develop steroid resistance. These patients with late steroid resistance (LSR) are often treated with immunosuppressant medications, but the effect of these additional drugs on the long-term prognosis of LSR is still unknown. METHODS: A retrospective chart review was performed on patients diagnosed with idiopathic NS and subsequent LSR during the 8-year study period from 2002 up to and including 2009, with a minimum of 2 years of follow-up. Primary outcome measures were proteinuria and renal function. RESULTS: A total of 29 patients were classified as having LSRNS. The majority of patients received treatment with calcineurin inhibitors and/or mycophenolate mofetil. Seven patients received three or more non-steroid immunosuppressant medications. Sustained complete or partial remission was achieved in 69 % of patients. Three developed end-stage renal disease, and all others maintained normal renal function. There were 13 episodes of serious adverse events, none of which were fatal or irreversible. CONCLUSION: Most patients with LSRNS responded to immunosuppressive therapy by reduction or resolution of proteinuria and preservation of renal function. The results suggest that immunosuppressive treatment is a viable option in NS patients who develop LSR.