A technique of esophageal cannulation used in rats was adapted for use in the sub-human primate. Cannulation of the esophagus requires general surgical skills and a very short postoperative recovery period. No interference in eating habits or tendency toward vomiting was noted following cannulation. This technique allows the investigator an effective method for oral dosing of drugs with minimal physical and emotional stress to the animals and is quite appropriate for oral drug self-administration studies.