Sixty nine of bilharzial and non bilharzial stone formers, with uniary oxalate calculi (71 stones), were categorized according to the chemical composition of stones into 4 groups. Biochemical and microbiological parameters for these groups were determined. It was found that urinary calculus was mostly found in patients suffered from bilharziasis (70.4%). Stone recurrence rate was frequently in 50.7% of patients with urinary tract infection. Pseudomonas, E. coli, Staphylococci and Enterococci were the common types isolated from urine and stone (surface) samples. The biochemical results demonstrated the significant increase in serum total protein and its fractions, (except albumin), in all groups, compared to the mean normal value., α₂- glycoprotein revealed significant increased value in groups 2 and 4 (with stones containing calcium phosphate. Significantly increased value of B-glycoprotein was obtained in groups 1 and 3 (calcium oxalate calcium phosphate (Ca Ox- CaP) or calcium oxalate uric acid (CaOx - U stoines). α₂ and β-glycoprotein were associated with high bacterial infection and incidence of acute inflammation. In the present work it could be confirmed that, bilharziasis increased the incidence of urinary tract infection and formation of stone. The stone recurrence rate was frequently high in the patients with chronie urinary tract infection, referring that the bacterial infection play an important role in the formation of stones.