Serum and urinary tumor necrosis factor-alpha (SeTNF and UTNF) and interleukin-6 (SeIL-6 and UIL-6) by ELISA method were determined in 99 patients with glomerulonephritis (GN): 13 with extracapillaris GN (ExGN), 38 with membranoproliferative GN (MPGN), 33 mesangial proliferative GN (MesPGN), 5 with focal segmental glomerulosclerosis (FSGS), 5 with membranous nephropathy (MN), 3 with minimal change nephropathy (MC) and in 32 healthy adults. The higher levels of Se TNF than those in the healthy were in 25 patients: in nearly all with ExGN, in 8 with MPGN and in single patients with other GN. In all patients with high SeTNF were many extra renal organs involvement. Measurable levels of UTNF were in 30 patients (30%) (in 12 with ExGN, 9 with MPGN, 7 with MesPGN, 1 with MN, and 1 with FSGS). Most patients with high SeTNF belonged to group I. The higher levels of SeIL-6 than those in healthy were in 17 patients belonging to group I, in which high SeIL-6 were in 3 patients with ExGN, 6 with MPGN, 3 with MesPGN, 2 with MN, and 3 with FSGS. Measurable urinary IL-6 levels were in 27 (27%) patients, mainly in group I, and in single patients in other groups. The majority of patients with ExGN and MPGN from group I and UIL-6 positive suffered from renal insufficiency and histologically had proliferative GN. We conclude that the elevation of TNF alpha and/or IL-6 in plasma may reflect a secondary consequence of immune cells activation while urinary TNF alpha and/or IL-6 may be secreted by activated glomerular cells. Thus, high levels of TNF alpha and/or IL-6 in serum of patients with GN and extra renal organs involvement, peculiary with infections, suggested antibiotics therapy, because infection may stimulated cytokines production and they are important in pathogenesis and progress of GN. High urinary levels of IL-6 and (or) TNF alpha in patients with proliferative GN suggest great disease activity and is useful in the evaluating of IS treatment.