Background: Inadequate oral intake and poor absorption result in malnutrition in obstructive jaundice. Both malnutrition and obstructive jaundice promote bacterial translocation from the gut. This study was designed to test the efficacy of tube feeding in preventing malnutrition and in decreasing the metabolic and microbiological adverse effects in obstructive jaundice. Methods: Forty adult mongrel dogs were studied and were allocated into one of four groups: group I (PO‐control) underwent sham ligation of the common bile duct (CBDL) and was fed ad libitum on Portagen (Mead Johnson, Evansville, IN); group II (PO‐CBDL) underwent CBDL and was ad libitum fed on the same formula; group III (FEG‐control) underwent sham CBDL and received forced esophagogastric feeding (FEG) with Portagen; and group IV (FEG‐CBDL) underwent CBDL and received FEG. All the animals underwent insertion of a F‐12 feeding tube to the stomach from an esophagotomy wound on day 1 and the tube was used for continuous enteral feeding with Portagen over 4 h/d from day 2 until day 13 in groups III and IV. Fourteen days later, blood samplings were done and a laparotomy was performed to obtain liver, mesenteric lymph nodes (MLN), and terminal ileum for quantitative bacterial culture. Bacterial translocation to MLN and liver was represented by log10 CFU/g of tissue in this study. Results: Both group II and IV animals with CBDL significantly lost body weight (p =.0001) and had a lower level of prealbumin (p =.0054). A significant increase in bacterial translocation to MLN and to liver occurred in groups II and IV (p =.0017 and.0268, respectively). Intestinal bacterial population was also higher in these two groups than in the other two controls (p = 0.0028). An increase in plasma ammonia level was found in dogs with CBDL (p =.0002) and in dogs with FEG (p =.003), compared with their respective controls. Three among 13 dogs in group IV died and no mortality occurred in the other groups (p =.223). Conclusions: Tube feeding fails to improve malnutrition in obstructive jaundice and is associated with intestinal bacterial overgrowth, promoting bacterial translocation to MLN and liver, precipitating liver dysfunction and consequently a higher mortality. (Journal of Parenteral and Enteral Nutrition 21:036–040, 1997) Copyright © 1997 by The American Society for Parenteral and Enteral Nutrition.