Fernandez J, et al. – Physicians designed this study to assess prevalence and characteristics of bacterial and fungal infections causing and complicating acute–on–chronic liver failure (ACLF), predictors of follow–up bacterial infections and effect of bacterial infections on survival. In ACLF, bacterial infections were extremely frequent. They were severe and correlated with intense systemic inflammation, poor clinical course, and high mortality. Within a short follow–up period, patients with ACLF were highly predisposed to develop bacterial infections and could benefit from prophylactic strategies.