This article reviews the role of cytokines and immunoglobulin isotypes in the clinical outcome of E. granulosus infection. The coexistence of elevated quantities of IFN-gamma, IL-4, IL-5, IL-6 and IL-10 observed in most of hydatid patients supports Th1 and Th2 cell activation in human hydatidosis. In particular, Th1 cell activation seems to be related to protective immunity, Th2 cell activation to susceptibility to disease. Analysis of immunoglobulin isotypes expression reveals that the percentage of IgE responses decreases in patients parallelling to their response to chemotherapy and, among the IgG isotypes, only IgG3 and IgG4 appear related to therapy.