The use of biological agents has grown exponentially in immune-mediated inflammatory diseases (IMID), often achieving a good control of disease progression and improving patients' quality of life. However, their use resulted in an increased risk of adverse events, including reactivation of chronic/latent infectious diseases. As for the risk of Cytomegalovirus (CMV) reactivation, very few data are available. We reviewed the literature reporting cases of CMV infection in IMID patients during biological therapy. Although the risk of CMV reactivation cannot be excluded, we concluded that there is no evidence to warrant CMV screening before starting a biological agent.