Enteroliths of the appendix originate as inspissated concretions of fecal material. If the size of the fecalith or the motility of the appendix is such that the fecalith remains in position for an extended period of time, calcium may be deposited on its surface. Stasis, particularly with bacterial infection, increases the likelihood of calcium deposition. The first radiological demonstration of a calcified appendiceal enterolith was reported by Weisflog in 1906. Since that time, approximately 155 cases have been recorded in the world literature. Acute appendicitis is the most common abdominal disease requiring surgical intervention; it is the cause of 17,000 deaths per year in the United States alone. Any factor, therefore, which will aid in the early diagnosis and management of appendicitis is of considerable importance. During the past five years, in the John Gaston Hospital, of Memphis, calcified appendiceal enteroliths were demonstrated by x-ray examination in 34 patients. The reason for presenting this series of cases is to show (a) that demonstration of the calcified appendiceal enterolith may be of considerable help in the differential diagnosis of the acute surgical abdomen, and (b) that the incidence of perforation is greatly increased by the presence of a calcified enterolith. Case Reports Case I: An 8-year-old colored girl was admitted to the hospital with a history of abdominal pain and diarrhea of two days duration. She was quite dehydrated and her temperature was 102°. The abdomen was somewhat distended and tympanitic, with diffuse tenderness and generalized muscle guarding. There was a leukocytosis of 20,450. Because of severe diarrhea and lack of localized findings, the clinical diagnosis was acute gastroenteritis. X-ray examination of the abdomen (Fig. 1) revealed an oval calculus, 1.6 cm. in its greatest dimension, overlying the lower part of the sacroiliac joint on the right. Calcification was limited to the periphery of the stone. Considerable gas was observed in the colon and in several loops of small intestine. In addition, there was radiological evidence of a moderate amount of free peritoneal fluid and the properitoneal fat line was partially obscured on the right side. A diagnosis of acute appendicitis with calcified appendiceal enterolith was made. Laparotomy revealed a gangrenous appendix with perforation. The calculus had been extruded through the perforation and was free in the abdominal cavity. Recovery was uneventful, the patient being discharged six days after admission. Case II: A 13-year-old colored male was admitted to the hospital complaining of pain in the left side of the abdomen at the level of the umbilicus; a rather ill-defined mass was palpated in that area. The white blood count was 14,750.