The sacculus rotundus is a specialized lymphoid structure of the distal ileum in lagomorphs at the ileo-cecal-colonic junction. This structure is composed of gut-associated lymphoid tissue. A 5-year-old male castrated, mixed-breed rabbit presented for anorexia. An approximately 2 cm, firm mass was palpable in the mid to caudal abdomen. Hematologic and biochemistry findings demonstrated a relative heterophilia, moderate lymphopenia, and mildly elevated ALT. Radiographs demonstrated gas-dilated loops of small intestine. A presumptive diagnosis of GI stasis was made. Outpatient treatment was initiated. After initial improvement, the rabbit returned 5 days later with anorexia. Repeat radiographs demonstrated improvement in the intestinal gas pattern. To identify an underlying cause of recurrent GI stasis, a contrast-enhanced CT was performed and revealed a lobular, mildly contrast-enhancing thickening of the wall of sacculus rotundus. Abdominal exploratory identified a 2cm x 1cm beige mass within the sacculus rotundus. The mass was adhered to the left lateral body wall and to the apex of the urinary bladder. The sacculus rotundus and associated mass were completely excised. Histopathology demonstrated lymphoid malignancy with bacterial ulceration and apparent amyloid production, suggestive of a B-cell origin. The patient re-presented one month later for progressive hyporexia and abnormal stool production. Humane euthanasia was elected. Necropsy identified an intra-abdominal abscess at the aboral aspect of the resection site, with several adhesions over the proximal cecum. Histopathology of the associated tissues demonstrated no evidence of residual neoplasia. This case documents the identification and removal of malignant lymphoma within the sacculus rotundus of a rabbit.