Abstract: A system and method for inserting a gastrostomy catheter through a passageway formed through the abdominal and stomach walls of a patient. The gastrostomy catheter is mounted onto a dilatation catheter with a dilatation member such as an inelastic balloon on the distal extremity thereof. An introducer needle is first advanced through the walls of the patient's abdomen and stomach into the interior of the stomach and then a guidewire is advanced through the inner lumen of the needle into the stomach interior. The gastrostomy catheter-dilatation catheter assembly is advanced over the guidewire until the balloon on the dilatation catheter is in proper position crossing both the abdominal and gastric walls. Upon inflation of the balloon on the dilatation catheter, the passageway is expanded enough so that the gastrostomy catheter can be advanced therethrough to dispose the distal end of the gastrostomy catheter within the interior of the stomach.