Objective: To evaluate effects of Continuous low dose antibiotic prophylaxis versus no antibiotics in the patients with DJ stents with respect to urinary tract infection (UTI and biofilm formation. Material and Methods: A prospective randomized study in 36 patients being stented for stone disease, pelvi-ureteric junction obstruction (PUJO), were divided into 2 groups. Group 1 containing 18 patients received T. Nitrofurantoin 100mg once a day after stenting and Group 2 containing 18 patients received no antibiotic after stenting. Both the groups received pre-op single dose intravenous (IV) Levoflox and Amikacin according to their body weight. After stent removal, stents were sent in normal saline for evaluation of Culture and Biofilm formation. Positive stent cultures were processed for the formation of biofilm using Christensen's Tube method. Results: 2 out of 18 pre-stent removal cultures in group 1, 7 out of 18 pre-stent removal cultures in group 2 were positive. Biofilm was not detected in any of the groups. Febrile urinary tract infection was not seen in any of the groups. Dysuria and pain abdomen were most common presenting symptoms in stented patients. Conclusion:The incidence of infection in both the groups is same. There was no added advantage of prophylactic antibiotics for patients on DJ-stent. Unnecessary and irrational use of antibiotics should be avoided to prevent bacterial resistance in future. Studies on antibiotic prophylaxis in patients on DJstents are sparse. Larger studies are required to confirm the findings.