Overuse and misuse of broad-spectrum antibiotics increases the risks for the disruption of normal bacterial flora and the development of antimicrobial resistance. Oral broad-spectrum antimicrobials, such as quinolones, cephalosporins, and macrolides, were more frequently prescribed in Japan than in Europe or the United States. In particular, the use of oral quinolones was increased from 2009 to 2013 in Japan. Therefore, the National Action Plan on antimicrobial resistance was formulated in April 2016; it aimed to reduce oral broad-spectrum antimicrobial use by 50% by 2020. We opted to promote appropriate quinolone use through lectures for all medical staff including physicians. This study aimed to evaluate the trend of the oral quinolone use and the susceptibility of Escherichia coli and Klebsiella pneumoniae from 2013 to 2020 in our hospital. To investigate oral antibiotic use, the monthly median days of therapy per 100 patient days were investigated among inpatients and outpatients, excluding those with chronic diseases that required long term quinolone prescriptions. Additionally, the data on susceptibility of E. coli and K. pneumoniae to levofloxacin were analyzed. The use of oral quinolones for outpatients had significantly decreased by approximately 50% from 2013 to 2020, but no significant differences were observed in the use of oral quinolones for inpatients and the susceptibility of the bacteria to levofloxacin. Further rigorous antimicrobial stewardship interventions are necessary for optimization of oral quinolone use and minimizing the prevalence of resistant pathogens.