A retrospective study was conducted of 49 patients with primary gastrointestinal lymphoma to analyze clinicopathological features, prognostic factors, and results of treatment. Intestinal lymphomas (63%) were more common than gastric lymphomas (29%). Endoscopic biopsy was diagnostic in 64% of gastric lymphomas, while 97% of intestinal lymphomas required laparotomy for diagnosis. Lymphoblastic (35%) and diffuse large cell (33%) lymphomas were the most frequent histologic types. Complete remission (CR) was achieved in 61% of patients, with a 5-year survival of 72% in those who achieved CR. The overall 5-year survival and disease-free survival were 47% and 40%, respectively. All disease-related mortality occurred within 2 years of diagnosis, with 79% occurring in the first year. There was no overall significant difference in survival between the different treatment groups. Stage, extent of surgical resection, response to treatment, serosal involvement, multimodality treatment, and performance status were significant prognostic factors. Achievement of complete remission and complete surgical resection were the most favorable independent prognostic factors on multivariate analyses.