Background and Objectives: Urolithiasis is a frequently occurring urological disorder associated with multiple etiological factors, out of which bacterial infection is one .A definite relationship is seen between the presence of bacteria and activity of bacterial urease in development of stones .This study was thus undertaken to analyse the renal stones and their association with different bacteria. Materials and Methods: The study was conducted in a tertiary care center in North East India. 95 stones were collected intraoperatively. Upon removal, the stones were placed immediately in a sterile container and bacteriological analysis was performed by standard conventional methods. Results: Among the 95 stones analysed from 95 patients and 35% belong to age group 21-30 years with male: female ratio was 1.2:1 and 60% showed growth of organism and from one stone 2 organisms were isolated. Preoperative urine analysis showed growth in 52% of the patients and among these renal stone culture was positive in 82.2%. .Urease splitting organisms isolated from pre operative urine was 42.2% and that from renal stones was 60%. Conclusion: Infection of renal calculi with multiple drug resistance strains might reflect treatment failure. Bacteria present within the calculi may not be detected by urine culture, and may act as foci of persistent infection of the urinary tract.