Twenty-six patients with non-Hodgkin's lymphoma (NHL) born in Ehime Prefecture were classified immunofunctionally by testing E, EA and EAC rosettes, surface immunoglobulin, Ia antigen and terminal trasferase (TdT) of lymphoma cells. Geographical distribution of the immunofunctional cell type, clinical stage and PPD and PHA skin test values was examined. According to cell type, there were those types of patients: 13 cases of the T-cell type (50%), 10 cases of the B-cell type (38%) and 3 cases of the Null-cell type (12%). There was no true histiocyte type. In the geographic study, the percentage of the T-cell type in the Matsuyama district was less than that in Kyushu island, but more than that in the northeast part of Japan. The number of T-cell type patients was much larger in the southwest part of the prefecture. B-cell type patients in stage I or II and T-cell type patients in stage III or IV were predominant. Rare cases of the T-cell type with EA or EAC rosetting were observed. Cells from Null-cell type patients and a T-cell type patient with diffuse lymphoblastic histology were TdT-positive, but others were negative. PPD and PHA skin tests showed a much weaker reaction in the T-cell type than in the B- and Null-cell types.