Helminths are multicellular eukaryotic parasites that infect over one quarter of the world’s population. Through coevolution with the human immune system, these organisms have learned to exploit immunoregulatory pathways, resulting in asymptomatic tolerance of infections in many individuals. When infections and the resulting immune responses become dysregulated, however, acute and chronic pathologies often develop. A recent international meeting focused on how these parasites modulate host immunity and how control of parasitic and immunopathological disease might be achieved.