Autoimmune lymphoproliferative syndrome (ALPS) is a genetic disorder clinically characterized by chronic non-malignant lymphoproliferation and autoimmunity manifestations. The majority of patients with ALPS have mutations of the gene coding for the FAS receptor, which in normal conditions after integration with its ligand FASL, induces lymphocyte apoptosis. Mutations in genes encoding FASL or Caspase 10 (CASP 10) that activate the next step in programmed cell death were found in a handful of ALPS patients. Invalid lymphocyte homeostasis resulting from mutations in the FAS apoptotic pathway leads to autoimmunity and uncontrolled lymphoproliferation. Patients with ALPS commonly have lymphadenopathy, splenomegaly, cytopenias and multiple autoimmune disorders such as hepatitis, uveitis, encephalitis but glomerulonephritis is rarely observed. We describe a case of a 14-year-old boy with recurrent respiratory infections, lymphadenopathy, hepatosplenomegaly and pancytopenia, who developed glomerulonephritis. Due to the suspicion of ALPS, laboratory investigations were extended to specific immunological tests. They revealed an elevated double negative T-cell (DNT) count, an elevated level of vitamin B12 and hypergammaglobulinemia. Although these findings suggested ALPS, no mutations in the FAS or FASL genes were found, however, the CASP 10 mutation was not examined. He presented with microscopic hematuria followed by heavy proteinuria (6g/day) without clinical features of nephrotic syndrome. Consecutive treatment with corticosteroids caused an increase in hemoglobin, neutrophil and platelet levels after ten days of treatment and complete remission of proteinuria after eight weeks. Our report shows that kidney involvement in the form of glomerulonephritis sensitive to cortico-steroid treatment may be another feature of ALPS.