Primary gastro-intestinal lymphoma (PGIL) is the most common type of extra-nodal non Hodgkin's lymphoma. Their clinical and histological presentations are heterogeneous depending on the site of the lesion. There is no consensus regarding the role of surgery and chemotherapy in the therapeutic approach. In our country epidemiology of the disease is unknown with IPSID being the most frequent type. We report anatomo-clinical features and prognostic factors of PGIL and compare intestinal to gastric forms in our region. This is a retrospective study of 153 cases of PGIL in adults diagnosed and treated in the department of medical oncology in Farhat Hached Hospital between 1994 and 2006. The median age was 52 years and the sex-ratio 2.1. Tumor sites were gastric (67%), intestinal (26%) and gastrointestinal (7%). Abdominal pain (87%) followed by vomiting and diarrhoea (37 and 15%) were the most common symptoms. Performance status (PS) < 2 was seen in 80% of patients, high grade lymphoma in 70.5% of cases and B phenotype was noted in 85%. MALT lymphoma accounts for 50% of cases, and IPSID for only 5% of PGIL. About 47.5% of cases were stage IE, 138 patients had chemotherapy with an objective response rate of 77%. Only 46% of patients had surgery (14 for surgical complication, 6 for residual tumor after chemotherapy and 22 to have histological diagnosis). The five-year overall survival (OS) was 62%. In high grade lymphoma patients favorable prognostic factors for OS included young age < or = 60 years, PS < 2, normal serum LDH, hemoglobin > 12 g/dL, B phenotype, localised stage (IE-IIE1), anthracycline-based chemotherapy regimen, achieving complete or partial response to induction chemotherapy and no relapse. In multivariate study only relapse and PS were significant prognostic factors for OS. In low-grade lymphoma patients, none of these factors had a significant correlation with OS: age < or = 60 years, PS < 2, stage (IE-IIE1), response to induction chemotherapy, relapse. Compared to gastric lymphomas, intestinal cases occurred at a younger age, frequently with diarrhoea, weight loss, and occlusion. They are more often high-grade, T phenotype and have locally advanced stage (IIE); surgery is more common in this group. We conclude that stomach is the main site of PGIL in our region, intestinal lymphoma is less frequent and IPSID has become rare. Recent progress in chemotherapy has allowed good therapeutic results with a conservative approach. Surgery may be performed in case of emergency or for residual lesions after medical treatment.