B-lymphoblastic lymphoma is a neoplasm of immature B cells and is characterized by aggressive behavior and disease progression. Common sites of involvement are skin, lymph nodes, bone, soft tissues, breast, and the mediastinum. Gastrointestinal lesions are rarely encountered and therefore not fully described. We herein report the case of a 28-year-old male, who presented with abdominal pain and CT scan showed a tumor involving the small bowel and its mesentery. He underwent emergency laparotomy and enterectomy. Histopathology report revealed B-lymphoblastic lymphoma affecting the small bowel and the adjacent mesentery. This is the first documented case of a small bowel tumor diagnosed as B-lymphoblastic lymphoma in published literature.