CD30 is abundantly and selectively expressed on the surface of Hodgkin Reed-Sternberg cells, anaplastic large cell lymphomas (ALCLs), and other lymphoid malignancies as well as on several non-lymphoid malignancies including selected germ cell tumors. Expression of CD30 on normal cells is highly restricted, thereby allowing differential targeting of malignant cells. CD30, a member of the tumor necrosis factor (TNF)-receptor family has pleiotropic biologic functions, and antibodies targeting CD30 and other TNF family receptors can exhibit both agonistic and antagonistic signaling functions. Recently, antibody-drug conjugates targeting CD30, such as brentuximab vedotin, have shown striking activity in phase I and II trials, with manageable toxicity. This has defined an important emerging role for targeting of CD30 in the setting of Hodgkin lymphoma, ALCL, and possibly other CD30+ malignancies.