Cellular immunotherapy (CI), as we now know it, began in the early 1980s with the use of lymphokine-activated killer cells (LAK) and progressed to the use of the immunologically specific, tumor-infiltrating lymphocytes (TIL). TIL were shown to be particularly effective against melanoma and it was in these trials that we learned the importance of immunologic specificity for tumor. With the identification and characterization of tumor antigens recognized by TIL, we now see the use of these antigens in various forms constituting vaccines. Investigators are using tumor antigens alone or in combination with dendritic cells (DCs), the body's most efficient and powerful antigen-presenting cell. Therapies are being delivered to many patients with different types of cancer in order to combat bulky disease, eliminate micro-metastatic disease, and provide a memory mechanism to fight tumor recurrence. This review will detail the past 18 years and present the developments that have been made in this therapy. Many believe that with continued development, immunotherapy will provide a fourth modality of cancer therapy.