The surface of the erythrocyte undergoes a number of modifications during infection by Plasmodium falciparum. These modifications are critical for pathogenesis of severe disease and the acquisition of host immunity through their role in interactions between the host and the parasite and in antigenic variation. Our knowledge of the molecular basis for these processes has increased dramatically over the last few years, through a combination of genomic and biochemical studies. This review provides a summary of the molecules involved in cytoadherence and antigenic variation in P. falciparum.