SENIOR SURGICAL REGISTRARS, WESTMINSTER HOSPITAL GROUP, LONDON MOST swallowed foreign bodies are either arrested in the upper gastro-intestinal tract and are removed, or pass spontaneously with no further trouble. It is our experience that of those foreign bodies which pass the pylorus the dangerous ones are fish and chicken bones.Three cases of fish-bone perforation of the small bowel were seen b y one of us (B. S. A.) in less than 2 months while surgical registrar at St. James's Hospital, Balham (2 of them operated upon within 4 days). T h e records of that hospital for the 10-year period 1951-60 were searched for cases of swallowed foreign body. For the purposes of these observations, all which lodged in the oesophagus or stomach and were removed at oesophagoscopy or laparotomy were excluded. Also the blunt foreign bodies, such as coins in children (a commonplace and usually harmless incident), were excluded. This gave 18 cases of sharp foreign bodies which did not lodge in the throat, gullet, or stomach, but passed into the small intestine. Of these, 12 continued through the gut harmlessly and 6 caused a perforation.Sharp Foreign Bodies passed spontaneously. -Of the 12 which passed right through the gut, there were :-Three open safety-pins (2 young women from a local mental institution and I inmate from a nearby prison).Three ordinary pins (young girls of 13, 15, and 16 years, the latter swallowing 8 pins during convalescence after appendicectomy).T w o carpenter's nails (both psychiatric patients).One dressmaker's needle (girl aged 13 years) and one mail-bag needle (another prison inmate). Pieces of a broken mirror, swallowed b y a prisoner and subsequently removed from the rectum b y wash-outs.An assortment of foreign bodies, including sharp objects, which were swallowed by a dement, and all of which were passed safely.