Bowel perforation is an emergency problem, it presents as an acute abdomen. Computurize tomography (CT) is important imaging modality used to evaluate patients with acute abdomen. CT shows anatomical detail and intestinal wall, evaluating secondary signs of bowel disease within the surrounding mesentery and detecting even small amounts of extraluminal air or oral contrast leakage into the peritoneal cavity. The aim of this article is to illustrate acute abdominal CT findings due to FOLFIRI therapy of a patient with colorectal cancer. Interestingly, this patient was an emergency case based on radiologic findings, but he felt good, had no emergency problem clinically.