The objective of this study was to investigate the antitumor activity of selectively expanded γδ T cells in tumor-infiltrating lymphocytes (γδTILs) or tumor ascites lymphocytes (γδTALs) from patients with colorectal and ovarian epithelial carcinoma (OEC) in vitro and in vivo. γδTILs/TALs were expanded by the solid-phase antibody method; their cytolytic and proliferative activities in vitro were detected by the MTT method and 3 H-TdR incorporation and their effect in vivo was evaluated by the nude mice model. Expanded γδTILs from colorectal tumors demonstrated marked cytotoxicities to allogeneic human colon adenocarcinoma HR8348 and lymphoma Daudi cells, as well as xenogeneic murine thymoma EL-4 cell lines. Cytokines, including IL-2, IL-4, IL-12, IL-15, TNF-α and INF-γ, could promote the cytotoxicities of γδTILs to tumor cells, whereas IL-10, GM-CSF and TFG-β had no effect on such killing activities. Rested γδTILs could proliferate strongly in response to mitomycin C-treated Daudi and EL-4 tumor cells, but not to HR8348 tumor cells, suggesting that the latter might possess only cytotoxicity-related antigen recognized by γδTILs. Either αβTILs or γδTILs from patients with OEC displayed cytotoxicities to allogeneic or autologous OEC cell lines at a similar strength in vitro. Transferring γδTILs into Daudi cell-bearing BALB/c nude mice with an injection of IL-2 was able to maintain a high survival rate of the mice for 30 days, when compared with mice treated with αβTILs or without any treatment (p< 0.05). Without coinjection of IL-2, after 3 months of Daudi tumor inoculation, a high survival rate was observed in γδTIL-treated mice. Similarly, adoptive γδTALs from the ascites of patients with OEC transferred into nude mice displayed a stronger antitumor response to OEC SKOV3 cells than αβTALs in vivo. Tumor volumes in γδTAL-treated mice were smaller than in αβTAL-treated or non-TAL-treated mice within the period from day 23 to day 50 after tumor inoculation (p< 0.05). Fifty days after SKOV3 tumor inoculation, a decreasing trend of carcinogenic rate was observed in γδTAL-treated nude mice. Taken together, our results suggest that γδT cells could be a new candidate for adoptive immunotherapy in the future treatment of patients with cancer.