Background and Objectives: Despite modern antibiotic therapy and technological advances in lithotripsy, the presence of infection in patients withurinary stones, as well as with infectious stones is still a significant cause of morbidity and mortality.Methods; Patients admitted to the Urology Department who were diagnosed by the urologist as having urinary stones were included in this study. Bacteriological studywas conducted on pre–operative urine and operated renal stonesalong with chemical analysis of stones have been performed in 50 cases of urolithiasis. Results: The present study thus revealed that urolithiasis is pre­dominant in males. Of these, Bladder stones are found to be commonest followed by Kidney stones. Bacteriological analysis indicates that 20 stones showed  microorganism. The infection stones were recovered more in males. The  stones composed of calcium oxalate and calcium phosphate are more common. The commonest pathogen recovered from pre–operative urine culture and stone culture was E.coli (42.86% and 66.67%)from mixed stones composed of calcium oxalate with cal­cium phosphate and triple phosphate.Conclusion: The micro­organism can influence the stone forming process in many different ways. According to this view stone formation is a multifactorial and dynamic process.A knowledge of chemical composition of renalstones may be of great importance both as a guide for theclinical management and also for preventive measuresin reducing the risk of prevalence and recurrence of urolithiasis in this region.