The present study was carried to find out the role of bacteria in struvite stone formation and the associated biochemical abnormalities in the serum of patients. Thus, 16 struvite stone-formers were categorized into two groups according to the presence or absence of uric acid in the chemical composition of struvite stones. The changes in serum protein and glycoprotein were examined. Isolation and identification of bacteria were carried out for urine and the surface of the stone samples. It was noticed that the high level of α 2-, B-glycoprotein in serum may reflect acute bacterial infection and a sort of inflammation in many cases of the studied groups compared to 17 healthy normal persones. Surgically removed struvite stones were infected with urea-splitting bacteria especially Proteus mirabilis which was found in many samples ( 42.9%) of both urine and stones of patients with Calcium oxalate, Calcium phosphate, Magnesium ammonium phosphate and uric acid stones. This could be explained by the fact that the organism had been participating in the fomation of struvite stones. In some cases with struvite stones, associated with chronic urinary tract infection mixed bacteria (more than one organism) were commonly detected in urine samples.