Abstract Background Healthcare-associated infections (HAIs) are one of the most common preventable complications in hospitalised patients related to increased morbidity and mortality for patients. Proper hand hygiene (HH) can decrease the prevalence of HAIs within care settings. The aim of the study was to evaluate the effects of a monitoring and feedback system on HH compliance (HHC). Methods Three monitoring and feedback studies have been carried out in Umberto I teaching hospital of Rome since 2021. Healthcare workers (HCWs), were trained on how to carry out the direct observation on the 5 WHO moments on HH. The data collection lasted two weeks each year. Following data collection, they were analysed and discussed annually with HCWs. A multivariable logistic regression model was constructed to identify predictors of HH compliance. Results A total of 15874 HH were observed, of which 40.1% in 2023. The recorded HHC was 71.0% in 2021, 75.4% in 2022 and 71.6% in 2023. Multivariable analyses showed that HHC was positively associated with female sex of observed (aOR:1.3, 95% CI:1.1-1.4), during weekend days or holidays (aOR:1.3 95% CI:1.1-1.4) and all indications with respect to ‘before touching a patient’. Regarding the professional category of the observer, compared to physicians, midwives were more likely to report compliant observations (aOR=2.4, 95% CI: 1.4-4.1). On the other hand, a negative association was found with external ward staff and other HCWs and no-HCWs compared to physicians. Ward area and year of observation did not influence the probability of the outcome. Conclusions The results of this study revealed sub-optimal adherence to HH, with the lowest rates observed prior to patient interaction. That, coupled with the variability seen among HCWs, underlines the difficulties in achieving a uniform level of compliance. Therefore, ongoing training to raise awareness among HCWs and to repeat the survey over time identifying any major problems is essential. Key messages • Monitoring the reasons for non-adherence to hand hygiene in healthcare institutions in order to formulate strategies to improve HH adherence among hospital staff is essential. • Hand hygiene (HH) monitoring systems can produce measurable improvements in HH adherence by healthcare personnel, resulting in a reduction in the incidence of healthcare-associated infections.