A patient was admitted for a suspected appendicitis; occasionally, a roentgenogram of abdomen, an echography and a tomography: confirmed the suspect. At laparotomy a perforated diverticulum of cecum is suddenly reported: a segmentary resection of ascending colon is performed. Authors remark, according to literature, that preoperative diagnosis of perforated cecal diverticulum is difficult even today, in spite of diagnostic procedures.