Tumour infiltrating lymphocytes (TIL) have the capability of recognising and lysing autologous cancer cells, both in vitro and in vivo. Advanced non-small cell lung carcinoma (NSCLC) is partially insensitive to chemo radiotherapy and has a poor prognosis: thus, for this, an immunotherapeutic approach could be attempted. We expanded in vitro 46 out of 70 samples of TIL derived from NSCLC. From proliferating TILS, a number varying from 10 to 50 x 10(9) cells was obtained. These lymphocytes belonged to the T cell lineage, had the capability of growing for 45-60 days and lysed autologous better than allogeneic cancer cells. In addition, analysis of the restriction maps of T cell receptor (TRC)-beta, demonstrated that an oligoclonal population of T cells was preselected in vivo, near the tumour site, and might be expanded in vivo, using phytohaemagglutin and interleukin 2 while maintaining the same characteristics of the original population. These results give a clear rationale for the use of in vitro expanded TIL from NSCLC in protocols of adoptive immunotherapy in patients with residual disease following surgery.