Parvovirus B19 (B19V) has been associated with a wide spectrum of clinico-pathological disorders in human beings depending upon the host immunity. The present report describes a child with chronic myeloid leukemia ( CML) on hydroxyurea in haematological remission, who developed profound erythroid suppression following B19V infection requiring multiple transfusions and withdrawal of hydroxyurea. Despite being off-therapy the child remained in complete clinical and haematological remission till anti B19V antibodies appeared. This case illustrates the ability of B19V infection in suppressing neoplastic myeloid clone, a phenomenon not described earlier.