Hemozoin (malaria pigment) has been implicated in the modulation of immune responses during malaria infection. This study was designed to evaluate the effect of purified hemozoin on the in vitro activation of myeloid dendritic cells. Our study also revealed that in addition to enhancing the maturation of dendritic cells, hemozoin also greatly promotes immunoglobulin G2a antibody responses when coadministered with a DNA vaccine plasmid encoding Pfs25, a Plasinodium falciparum transmission-blocking antigen.