Assessing the risk of difficult-to-treat bacterial superinfections, such as multidrug-resistant (MDR) Gram-negative bacilli, according to comorbidities, lung abnormalities or systemic diseases, the severity of pneumonia and the risks of drug-related effects are crucial points for the clinical management. Despite the wide-and not always appropriate-use of broad-spectrum antimicrobials, specific data about bacterial and fungal co-infection in COVID-19 patients are lacking, and confirmed evidence is urgently required to build prospective evidence and to support the development of antimicrobial policy and appropriate stewardship interventions. The present Special Issue aims to focus on the following key points: Importance of superinfections in COVID-19 patients who are typically characterized by immunosuppression related to viral infection, need for prolonged hospitalization, treatment with immunomodulatory therapies (steroids, monoclonal antibodies, etc.); Their impact on the outcome of a cohort of patients who are relatively young, with few comorbidities, but requiring prolonged invasive support; Incidence, characteristics and impact of bacterial infections caused by multidrug-resistant, Gram-negative pathogens in the context of COVID-19 disease; Incidence, characteristics and impact of fungal infections, such as the most known invasive aspergillosis but also candidemia and/or other fungal infections (e.g., mucormycosis); Antimicrobial surveillance, control and management measures as implemented on a local, national and international basis.