Guidelines for the placement of percutaneous endoscopic gastrostomy (PEG) tubes are not available. We developed a decision-making algorithm by integrating the medical and ethical dimensions of the decision. According to our algorithm, physicians should not offer PEG tubes to patients with anorexia-cachexia syndromes. For patients with permanent vegetative states, physicians should offer and recommend against the procedure. For patients who have dysphagia without other deficits in quality of life, physicians should offer and recommend the procedure. For the the remaining patients who have dysphagia with other deficits in quality of life, the physician's role is to provide non-directive counselling regarding the short and long-term consequences of a trial of PEG tube feeding.