A retroperitoneal abscess is a rare condition that is difficult to diagnose and treat because of its insidious onset and non-specific clinical manifestations. A retroperitoneal abscess may have various causes, such as diverticulitis, perforated cancer, spinal infection, inflammatory bowel disease, pyelonephritis, peptic ulcer disease, pancreatitis, retroperitoneal appendicitis, trauma and post-instrumentation. We report a case of retroperitoneal abscess related to colonic rupture with spinal destruction and thoracoabdominal wall extension.