Human Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Frequency of CMV infection and disease after allo-HSCT depend on several factors including virus-host interactions, recipient-donor CMV serology, donor type (HLA-identical vs. haplo-identical donors)and intensity of conditioning regimens. Moreover, monitoring strategies, cutoff values of viremia to guide prophylactic, preemptive, and treatment interventions remain to be determined. Broader knowledge in CMV biology and its relationship with the host immune-system is greatly contributing to develop novel therapeutic approaches including the application of novel antiviral drugs, with improved toxicity profiles currently under investigation in randomized phase II and III trials, and cell therapy approaches. Significant evidence of the clinical efficacy of adoptive T-cell therapy (ATCT) from CMV-seropositive donors is also emerging. Alternative methods allow ATCT also in allo-HSCT recipients of seronegative donors and cord blood grafts. Vaccine-immunotherapy has the difficult task to reduce the incidence of CMV reactivation/infection in immunocompromised allo-HSCT patients and reach CMV immune control. In this manuscript, we update a previous review by also including recent developments in the virology lab and their possible association with treatment strategies at bedside.