In this application is described the expression and purification of a recombinant Plasmodium falciparum (3D7) AMA-1 ectodomain. The method of the present invention produces a highly purified protein which retains folding and disulfide bridging of the native molecule. The recombinant AMA-1 is useful as a diagnostic reagent, for use in antibody production, and as a protein for use alone, or as part of, a vaccine to prevent malaria.