Porter1 presented the subject of chyle cysts of the mesentery before the Western Surgical Association twenty-six years ago. He reported a case of his own and discussed 20 cases, reports of which had appeared in the literature. He regarded the chyle cyst as a surgical rarity, and believed that it was less common than the serous mesenteric cyst. On examining the records of autopsies at the University of Minnesota recently, we found that in approximately 15,000 autopsies no case of chyle cyst had been recorded. In a search of the clinical records of St. Luke's and of St. Mary's hospitals, Duluth, representing a total of over 200,000 cases, we found that but 2 cases of chyle cyst had been recorded. In the Los Angeles General Hospital, according to Alesen,2 no such case was recorded from 1912 to 1929. Friend3 assembled 52 instances from 1875 to 1912; Benedict