In order to verify whether a telephone recall system directly managed by the pediatricians who usually follow up the children for their cancer, with influenza vaccine administered in the oncological clinic, is more effective than an anonymous recall system, 205 children with oncohematological malignancies were randomised to one of three intervention strategies for increasing influenza vaccination coverage. The results showed that all of the strategies were useful in increasing influenza vaccination coverage, but the efficacy of recall was optimal only in the children who had completed chemotherapy since less than six months.