Systemic lupus erythematosus (SLE) in children is usually more severe than it is in adults and there is a higher incidence of renal involvement. We described 18 children (16 girls, 2 boys) with lupus nephritis (LN), whose average age was 14.4 ±1.81 years. Disease activity was assessed according to SLEDAI (SLE Disease Activity Index). Renal biopsy was classified according to the INS/RPS (International Society of Nephrology/Renal Pathology Society). The patients were treated with steroids (100%) and pulses of cyclophosphamide (88.9%) or mycophenolate mofetil (11.1%), next azathioprine or mycophenolate mofetil with prednisone in reduced doses. In children with renal/multi-organ insufficiency and/or septicaemia, renal replacement therapy (27.8%), and plasmapheresis (22.2%) were used in the initial treatment. The SLEDAI initial activity was high in 44.4% and moderate in 55.6% of children. LN manifested as: nephrotic syndrome (83.3%), microhaematuria (100%), leukocyturia (60%), hypertension (72.2%), and acute renal injury (83.3%); mean GFR was 54.55 ±33.09 ml/min/1.73 m². In the renal biopsy, class IV LN according to INS/RPS was mainly diagnosed (82%). At the end of follow-up, mean observation time 32.1±23.36 months: mean GFR was 90.87 ±12.13 ml/min/1.73 m², proteinuria disappeared in 66.7% and decreased in 33.3% of children to the average of 1.7 g/day (range: 0.5-4.0 g/day), hypertension was observed in 83.4% of children. Intensive immunosuppressive treatment with pulses of cyclophosphamide in early stage of LN in children is very effective.