Type-2-cell-mediated immune responses play a critical role in mediating both host-resistance and disease-tolerance mechanisms during helminth infections. Recently, type 2 cell responses have emerged as major regulators of tissue repair and metabolic homeostasis even under steady-state conditions. In this review, we consider how studies of helminth infection have contributed toward our expanding cellular and molecular understanding of type-2-cell-mediated immunity, as well as new areas such as the microbiome. By studying how these successful parasites form chronic infections without overt pathology, we are gaining additional insights into allergic and inflammatory diseases, as well as normal physiology. Type-2-cell-mediated immune responses play critical roles in regulating host resistance against helminths and promoting tissue repair and metabolic homeostasis. Harris and Loke review recent advances in the field resulting from studies of helminth-host interactions and provide insight into the activation and function of type 2 immune cells.