Varicella may be a severe infection in children with malignancy. Varicella vaccination is either not recommended for immunocompromised children or it requires temporary discontinuation of immunosuppression. We prospectively evaluated the feasibility of a varicella vaccination programme of household contacts of varicella-negative children receiving antineoplastic chemotherapy. From April 2004 to April 2005, 207 children were evaluated; in 49 (24 percent) the attending physicians collected no history about previous varicella and performed no serological evaluation before any transfusion. Among the 158 patients with complete history and/or a screening test, 51 (32 percent) were negative, with a total of 110 household contacts eligible for the study. Of these, 13 (12 percent) subjects resulted negative for varicella. In three of them vaccination was not performed due to parental refusal. This study demonstrates the difficulties in implementing a varicella vaccination programme targeting negative household contacts of immunocompromised children. The attitude of paediatric oncologists and parental refusal currently represent the main challenges against the complete success of this strategy in countries where VZV vaccination is not inserted in the general vaccination programme.