Renal biopsy was performed on 28 out of 50 children with primaJY nephrotic syndrome encountered during the period January 1994-December 1995. Light microscope (LM) and immunofluorescence microscope (IM) examinations were performed on all b1opsy specimens. LM examination indicated minimal changes (MC) in 13 cases (46.4%), focal segmental glomerulosclerosis (FSGS) in 10 (35.7%), membranous glomerulonephritis (MG) in 2 (7.1%), mesangial prolifemtive glomerulonephritis (MPG) in 7 (7.1%}, and membranoprolifemtive glomerulonephritis (MPGN) in 1 (3.6%). On IM examination, immunoglobulin deposit was not detected in any MC patients, whereas in FSGS, IgG, IgM, C3 and fibrinogen deposits were found. In the MG group, IgG deposition was detected in one case. In the MPG cases, depositions of IgA, IgG, IgM, C3 and fibrinogen were detected and in the c..ase of MPGN, deposits of IgM and C3 were found. Regarding to response to steroid treatment in the MC group, there was a significant difference between the steroid sensitive and steroid insensitive (p<0.05). For the FSGS abnormality in the steroid treatment of the insensitive patients, there was found significant difference with the steroid sensitive abnormality (p<0.05}. In conclusion, nephritic symptoms (hematuria, proteinuria. , azothemia} are possibly the non minimal group and hence, it would be necessary to cany out renal biopsy to prove this.