We retrospectively investigated 59 surgically resected primary intestinal diffuse large B-cell lymphomas (PI-DLBCL) including 31 males and 28 females with a median age of 66. Eleven (19%) tumors were perforated at presentation; 8 (14%) were multicentric. Ileum (n=24; 43%) and ileocecum (n=17; 30%) were most frequently involved. Twenty-one (36%) patients did not receive chemotherapy or radiotherapy including 6 with perforation and died in 0.2 to 7 months. The 1-, 2-, and 5-year overall survival rates were 68.4%, 56.5%, and 50.0%, respectively. Seven (12%) of 59 cases were positive for Epstein-Barr virus (EBV) by in situ hybridization. IGH, BCL2, BCL6, and MYC foci were rearranged in 22%, 3%, 17%, and 7% cases, respectively, with 14% exhibiting gain/amplification at the MYC locus. Perforation (P=0.009), high ECOG PS (≥2) (P=0.018), and no adjuvant chemotherapy (P<0.001) were poor prognostic factors but not immunophenotype including co-expression of bcl-2 and myc, EBV status, or chromosomal aberrations. Perforation and chemotherapy remained significant by multivariate analysis. PI-DLBCL in Taiwan carried a relatively higher rate of perforation, lower frequency of germinal center B-cell phenotype, and higher EBV association as compared with studies from other geographic areas. Furthermore, perforation was a poor prognostic factor.