The emergence of antibiotic resistance as a consequence of inappropriate use results in higher mortality rates and has become a major public health challenge worldwide. Antimicrobial stewardship programs (ASPs) aim to ensure proper use of antimicrobials and reduce health care costs. We assessed the impact of using a behavioral approach during a persuasive ASP on antibiotic appropriateness, consumption and costs. We conducted a prospective interventional cohort before-and-after study in the intensive care unit (ICU) of a 554-bed, university teaching hospital in Terni, Italy, 14 of which are located in the ICU. We describe a 10-month persuasive ASP intervention model used in a referral ICU with daily rounds. The aim of the study was to improve medication appropriateness through educational action and reduce the consumption of carbapenems and echinocandins by conducting post-prescription reviews, prescribing reviews and holding daily discussions with the ICU team. We analyzed the prescribing appropriateness of the ICU team in accordance with the decisions made by the Antimicrobial Stewardship (AMS) team to improve the quality of antibiotic prescribing during the first five months and the last five months of the surveillance period. The results were expressed as the defined daily dose (DDD) per 100 occupied bed-days and costs. The data were compared with those previously obtained during the pre-educational period (the year before ASP implementation). Comparisons were made between the decisions taken to improve antimicrobial treatments administered during the first half of the surveillance period (March-July) and those administered during the second half (August-December). In all, 116 decisions were made from March to July while only 65 were made from August to December (p-value 0.00001). A significant reduction was observed in the consumption of carbapenems and echinocandins (11.15% and 25.62%, respectively). Total antibiotic cost savings amounted to 57,541.16 euros. The persuasive ASP strategy positively influenced the prescribing behavior of physicians, thus improving the appropriateness of antibiotic therapy and reducing antimicrobial consumption.