To evaluate the correlation of clinical, laboratory, and pathological features at pre-sentation of focal segmental sclerosis (FSGS), we reviewed in a cross sectional study the pathological findings of kidney biopsies in 64 cases of primary FSGS, and correlated them with the clinical and laboratory data obtained at the time of the biopsies. The data included blood pressure, glomerular filtration rate (GFR), serum albumin, and the level of proteinuria. The mean level of serum creatinine was significantly higher in the biopsies' findings of synechiae (adhesions) in the Bowman's capsule, interstitial fibrosis, and global scars (P< 0.05), and mean level of GFR was significantly lower with the presence of interstitial fibrosis (P< 0.05). Furthermore, there was a positive correlation between the level of serum creatinine and global sclerosis (r= 2.21, P= 0.04), and a negative correlation between the level of GFR and global sclerosis(r= 2.01, P= 0.02). All the patients with renal insufficiency had interstitial fibrosis in their biopsies in comparison of only the 24 patients (48%) of the group without renal insufficiency (P< 0.05). There was no significant difference between patients with and without hypertension and nephritic-ranged proteinuria. We conclude that we found a correlation of renal insufficiency in primary FSGS patients with interstitial fibrosis, global scars and the synechiae of Bowman's capsule in their biopsies.