Background: The COVID-19 pandemic has challenged health systems worldwide since 2020. At the frontline of the pandemic, healthcare workers are at high risk of exposure. Compliance with infection prevention and control (IPC) should be encouraged at the frontline. This systematic review aimed to assess the effects of dissemination interventions to improve healthcare workers' adherence with IPC guidelines for respiratory infectious diseases in the workplace.Methods: We searched CENTRAL, MEDLINE, Embase, and the Cochrane COVID-19 Study Register. We included randomized controlled trials (RCTs) and cluster RCTs that assessed the effect of any dissemination strategy in any healthcare settings. Certainty of evidence was assessed using the GRADE approach. We synthesized data using random-effects model meta-analysis in Stata 14.2.Results: We identified 14 RCTs conducted from 2004 to 2020 with over 65,370 healthcare workers. Adherence to IPC guidelines was assessed by influenza vaccination uptake, hand hygiene compliance, and knowledge on IPC. The most assessed intervention was educational material in combined strategies (plus educational meetings, local opinion leaders, audit and feedback, reminders, tailored interventions, monitoring the performance of the delivery of health care, educational games, and/or patient-mediated interventions). Combined dissemination strategies compared to usual routine improve vaccination uptake (risk ratio [RR] 1.59, 95% confidence interval [CI] 1.54 to 1.81, moderate-certainty evidence), and may improve hand hygiene compliance (RR 1.70; 95% CI 1.03 to 2.83, moderate-certainty). When compared to single strategies, combined dissemination strategies probably had no effect on vaccination uptake (RR 1.01, 95% CI 0.95 to 1.07, low-certainty), and hand hygiene compliance (RR 1.16, 95% CI 0.99 to 1.36, low-certainty). Knowledge of healthcare workers on IPC improved when combined dissemination strategies were compared with usual activities, and the effect was uncertain in comparison to single strategy (very low-certainty evidence).Conclusions: Combined dissemination strategies increased workers' vaccination uptake, hand hygiene compliance, and knowledge on IPC in comparison to usual activities. The effect was negligible when compared to single dissemination strategies. The adoption of dissemination strategies in a planned and targeted way for healthcare workers may increase adherence to IPC guidelines and thus prevent dissemination of infectious disease in the workplace.Trial Registration: Protocol available at http://osf.io/aqxnp . [ABSTRACT FROM AUTHOR]