BACKGROUND: Urinary tract infections (UTI) are one of the most common infections in humans. Antimicrobial drug resistance is one of the major threats due to wide spread use of inappropriate and empirical antibiotic therapy. The present study highlights the organisms causing UTI and their antimicrobial susceptibility pattern among patients attending a Tertiary Care Hospital in Eastern Bihar. MATERIALS AND METHODS: A total of three hundred and ninety two (392) samples of urine from patients attending different inpatient and outpatient departments were included in the study. Urine samples were inoculated on Nutrient agar, Blood agar and McConkey agar plates by streaking. Inoculated plates were then incubated aerobically at 37 degrees C for 24 hours. After 24 hours of incubation, isolated colonies were picked up and Gram staining was done. Motility test and other biochemical tests were done for further identification of bacterial isolates using suitable Controls. Finally Antibiotic Susceptibility Test (AST) was performed to detect the degree of sensitivity or resistance of the pathogen isolated from the patient to an appropriate range of antimicrobial drugs on Mueller-Hinton agar (MHA) plates by Kirby-Bauer disc diffusion technique. RESULTS AND CONCLUSION: Out of the total of three hundred and ninety two (392) samples from an equal number of patients received and examined in the laboratory during the study period only one hundred and thirty seven (137) patients were found to have bacteriological infection. Among the bacteriologically positive cases, UTI was more common in females. Among the bacterial isolates Escherichia coli was the commonest pathogen in both males and females, followed by Staphylococcus saprophyticus in males, and Staphylococcus aureus in females. Gatifloxacin was the most effective antibiotic in vitro for the Gram Negative bacilli isolated, while Azithromycin was most effective against the Gram Positive cocci. The Gram Negative uropathogens showed a high degree of resistance to cephalosporins, while the Gram Positive cocci showed highest resistance to Norfloxacin, and also to a lesser extent, to the cephalosporins. It is due to the excessive use of antimicrobials for all sorts of infections, that uropathogens responsible for UTI are increasingly showing resistance to antibiotics. The knowledge of uropathogens and their antimicrobial susceptibility pattern in this geographical region will help in appropriate and judicious antibiotic usage in our health care setup.