Catheter-associated urinary tract infections (CAUTIs) are among the most prevalent healthcare-associated infections, posing substantial clinical and economic burdens. The increasing incidence of antimicrobial resistance among uropathogens further complicates their management, necessitating region-specific surveillance to inform therapeutic strategies. This study aimed to assess the bacterial etiology and antibiotic resistance patterns of CAUTIs over a five-year period in a tertiary referral hospital in northern Iran. A retrospective cross-sectional analysis was conducted on ۱۵۸ hospitalized patients diagnosed with CAUTIs from ۲۰۱۸ to ۲۰۲۴ at Razi Educational and Medical Center. Urine samples were processed using standard microbiological techniques, and antimicrobial susceptibility testing was performed via the Clinical and Laboratory Standards Institute (CLSI) recommended disk diffusion method. Demographic, clinical, and microbiological data were analyzed using descriptive statistics. The majority of cases were male (۵۳.۳%), with a mean age of ۶۳ ± ۱۴.۹۵ years. Escherichia coli was the most frequently isolated pathogen (۵۵.۷%), followed by Klebsiella spp. (۱۷.۷%) and Citrobacter spp. (۱۲%). High resistance rates were observed among Enterobacteriaceae, particularly against cefixime (۸۰.۵%), trimethoprim-sulfamethoxazole (۷۹.۵%), and ciprofloxacin (۷۳.۹%) for E. coli. Nitrofurantoin (۱۸.۲%) and amikacin (۳۰.۲%) with lowest resistance remained the most effective agents. E. coli remains the dominant CAUTI pathogen and exhibits high resistance to commonly prescribed antibiotics, underscoring the urgency of local resistance surveillance. Nitrofurantoin and amikacin shows promise as an effective treatment option. These findings highlight the need for targeted antimicrobial stewardship, infection control practices, and continuous regional monitoring to control resistance trends and optimize patient outcomes.Catheter-associated urinary tract infections (CAUTIs) are among the most prevalent healthcare-associated infections, posing substantial clinical and economic burdens. The increasing incidence of antimicrobial resistance among uropathogens further complicates their management, necessitating region-specific surveillance to inform therapeutic strategies. This study aimed to assess the bacterial etiology and antibiotic resistance patterns of CAUTIs over a five-year period in a tertiary referral hospital in northern Iran. A retrospective cross-sectional analysis was conducted on ۱۵۸ hospitalized patients diagnosed with CAUTIs from ۲۰۱۸ to ۲۰۲۴ at Razi Educational and Medical Center. Urine samples were processed using standard microbiological techniques, and antimicrobial susceptibility testing was performed via the Clinical and Laboratory Standards Institute (CLSI) recommended disk diffusion method. Demographic, clinical, and microbiological data were analyzed using descriptive statistics. The majority of cases were male (۵۳.۳%), with a mean age of ۶۳ ± ۱۴.۹۵ years. Escherichia coli was the most frequently isolated pathogen (۵۵.۷%), followed by Klebsiella spp. (۱۷.۷%) and Citrobacter spp. (۱۲%). High resistance rates were observed among Enterobacteriaceae, particularly against cefixime (۸۰.۵%), trimethoprim-sulfamethoxazole (۷۹.۵%), and ciprofloxacin (۷۳.۹%) for E. coli. Nitrofurantoin (۱۸.۲%) and amikacin (۳۰.۲%) with lowest resistance remained the most effective agents. E. coli remains the dominant CAUTI pathogen and exhibits high resistance to commonly prescribed antibiotics, underscoring the urgency of local resistance surveillance. Nitrofurantoin and amikacin shows promise as an effective treatment option. These findings highlight the need for targeted antimicrobial stewardship, infection control practices, and continuous regional monitoring to control resistance trends and optimize patient outcomes.