Recent new developments in diagnostic techniques, prophylaxis and therapy of CMV infections have improved our possibilities to reduce the morbidity and mortality from CMV infections after BMT. The CMV symposium at the 19th annual EBMT meeting addressed several of the issues. PCR based or modified hybridization (FLASH) techniques were shown to be both more sensitive and to detect CMV infection earlier than standard culture. Since several different techniques are available, standardization is urgently needed to allow comparative studies. Other studies presented at the symposum addressed prophylaxis and early therapy issues such as the use of seronegative blood products for prevention of primary infection, the functional capacity of prophylactic immunoglobulin, the use of acyclovir prophylaxis, and a non-randomized comparison of ganciclovir and foscarnet for therapy of CMV antigenemia.