We investigated the clinical efficacy of locoregional and systemic adoptive immunotherapy (AIT) with or without interleukin-2 (IL-2) against solid metastatic lesions from digestive tract cancer. Eighteen patients, who were treated with more than 10(10) lymphokine-activated killer (LAK) cells, were enrolled in this study. Seven of the 18 patients received hepatic arterial infusion (HAI) of LAK cells with or without IL-2 against metastatic liver tumors (locoregional therapy group). The remaining 11 patients received systemic transfer of LAK cells with IL-2 against metastatic lesions located in organs other than the liver (systemic therapy group). Three of 7 locoregional therapy group patients showed clinically significant tumor regressions that were evaluated as being equivalent to partial response (PR). Two of the 11 systemic therapy group patients showed significant tumor regressions, but this response rate was much lower than that of the locoregional therapy group. The 2 effective cases in the systemic therapy group were esophageal cancer patients. Locoregional AIT with or without IL-2 against liver metastases from digestive tract cancer could be an effective therapeutic modality in some patients who are refractory to conventional therapies (e.g., chemotherapy and radiotherapy). It is necessary to find a new way to augment the anti-tumor effect of this therapy in combination with prior or concomitant chemotherapy.