We reviewed the medical records of 79 patients with primary gastrointestinal lymphoma (GI-NHL), defined according to the criteria of Dawson et al. (without involvement of liver, spleen, peripheral or mediastinal lymph nodes, or bone marrow), observed and treated in our institution between 1973-90. The most common disease site was the stomach (70 patients), followed by the small bowel (five patients) and the large bowel (four patients). The stage was IE in 36 cases and IIE in 43. Radical surgery or surgical debulking was the main therapeutic approach (67 patients); 12 patients received only chemotherapy, eight of whom had tumors considered unresectable at laparotomy. After surgery, most of the patients received chemotherapy; radiotherapy (RT) was given to only four patients. Surgically calculated overall survival (OS) rates at 5 years for the patients treated with surgery plus chemotherapy were 64% (radical surgery) and 46% (surgical debulking with microscopic lymphoma residue). For the 12 patients treated with chemotherapy alone, OS at 5 years was 0%. Our findings, in accordance with most published data, suggest that surgery, together with stage and tumor size, remains an important prognostic factor of survival in primary GI-NHL, especially when it is radical. In patients with negative prognostic factors (bulky disease, high-grade histologic type, microscopic residue, and stage II), postoperative chemotherapy and RT decrease the risk of distant failure and local recurrence.