The notion that immunocompetent cells, contained within adult bone marrow or peripheral blood, are capable of mediating an antitumor effect was first validated experimentally in 1957. T-cell immunotherapy for malignant disease is now routinely used in the context of allogeneic bone marrow transplantation. After 50 years of investigations into the use of T-cells for cancer therapy, adoptive cellular immunotherapy for cancer has progressed from the delivery of unspecific cellular products to the transfer of engineered tumor-specific T-cells. Adoptive cellular immunotherapy for cancer has now reached a stage of increasing feasibility and efficacy.