The structure and function of the human T-cell rearranging gamma gene are not completely understood. Several reports have suggested that this gene rearranges specifically in normal T cells, but the pattern of rearrangement in human lymphoid neoplasms is not clear. Some authors have described the rearrangements of this gene in unmanipulated leukemias as relatively specific for T-derived tumors, whereas others were unable to observe such specificity in malignant lymphomas. The present paper reports the analysis of the structure of the gamma gene in 32 lymphoid samples of different origin, with emphasis on non-T lymphomas. Four out of four T-cell lymphomas had this gene rearranged, whereas none of the 17 cases of B-cell lymphomas, 5 of Hodgkin's disease or 6 of nonneoplastic lesions showed any alterations of the gamma gene. Therefore, our data support the relative specificity of the gamma gene rearrangements in human T-cell malignant proliferations.