Perforation of a gastric ulcer due to a trichobezoar is an extreme rarity. We are reporting the seventh such case and, to our knowledge, the first in which a patient survived. Of the 172 cases of trichobezoar comprehensively analyzed in 1938 by DeBakey and Ochsner,1only 15 (9.6 per cent) had associated ulceration and five (2.9 per cent) were complicated by perforation. Between that date and Dec. 13, 1948, only 13 additional cases of trichobezoar have been recorded, and only one of these was reported to have been complicated by ulceration and perforation.2 Bezoars are masses of extraneous material that are usually found in the stomach or, rarely, in the intestines of man and certain animals. These are classified as trichobezoars (hair balls), phytobezoars (masses of indigestible vegetable and fruit residue, usually due to eating persimmons), trichophytobezoars (masses of hair and food residue) and concentrations (calculi due to