The present invention relates to methods and compositions for the treatment of Hodgkin's Disease, comprising administering proteins characterized by their ability to bind to CD30, or compete with monoclonal antibodies AC10 or HeFi-1 for binding to CD30, and exert a cytostatic or cytotoxic effect on Hodgkin's Disease cells. Such proteins include derivatives of monoclonal antibodies AC10 and HeFi-1. The proteins of the invention can be human, humanized, or chimeric antibodies; further, they can be conjugated to cytotoxic agents such as chemotherapeutic drugs. The invention further relates to nucleic acids encoding the proteins of the invention. The invention yet further relates to a method for identifying an anti-CD30 antibody useful for the treatment or prevention of Hodgkin's Disease.