A technique of nasoduodenal (N-D) intubation and intestinal decompression was developed and used in the horse to explore the prevention of gastric and intestinal distention after abdominal surgical operation. Three styles of tubes (2 single-lumen tubes and 1 double-lumen tube) were positioned in the duodenum of 12 mature horses (10 experimental and 2 clinical) during laparotomy (without enterotomy), and an iatrogenic occlusion at the small intestine was created and later released in the 10 experimental horses. The 2 clinical horses had an exploratory laparotomy to correct a natural obstruction of the small intestine. After each horse recovered from surgical manipulation, suction was used to keep fluids from accumulating in the cranial part of the gastrointestinal tract. In 5 of the 12 horses, the most simple N-D tube was positioned successfully and functioned properly. Three of the 5 horses which were fasted before surgical manipulation (to obtain an empty stomach) survived without postsurgical complications. Volume of reflux material was measured. Clinical data, such as periods of comfort during decompression without giving analgesics, were recorded. Necropsies were done on 10 of the 12 horses (9 experimental and 1 clinical). Although already tested in 2 clinical horses, use of the N-D tube remains experimental, and the N-D tube functioned only in horses which were fasted before surgical manipulation. Perfection of a safe and dependable means of emptying the equine stomach of its solid ingesta before gastrointestinal intubation is done, is the next step in affording greater clinical application of the N-D tube for gastrointestinal decompression.