Sixty-seven patients with non-Hodgkin's lymphoma of the digestive tract with locally advanced disease (stage II) were analyzed to determine the main factors influencing survival. There were 19 patients with stage II E1 and 48 with stage II E2 disease (Musshoff classification). According to the Kiel classification, 46 percent were low grade, 46 percent were high grade, and 8 percent were unclassified. The principal sites involved included the stomach: 11 cases, small intestine: 21 cases, colon: 12 cases, and mesentery: 11 cases. Lymphoma was unique in 45 cases (67 percent). Treatment consisted of laparotomy in 61 of 67 cases: partial resection was achieved in 21 cases, complete resection in 27 cases, and exploration only in 13 cases. Chemotherapy, according to histopathological subtypes, was employed in 90 percent of cases. Radiation therapy was applied in 25 patients (37 percent), essentially when there was residual disease after surgery (17 patients). Therapeutic indications were dependent on histological subtype, extension, and the therapy regimen in use at the time of treatment. Five patients were treated by surgery only, 2 by surgery and radiation therapy, 37 by surgery followed by chemotherapy, and 23 by all three treatment modalities. Overall survival was 62 percent at 5 years. Univariate analysis showed that 5-year survival rates were not influenced by sex, age, histopathological subtype (low grade: 69 percent; high grade: 59 percent; NS) or local extension (stage II E1: 76 percent vs stage II E2: 59 percent; NS). In contrast, complete surgical excision (p = 0.06) and radiation therapy in case of local residual disease (p = 0.02) seemed to improve survival. The main prognostic factor was the achievement of a complete therapeutic response (CR) (p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)