A review and updated report of an ongoing prospective investigation of two different adjustable silicone gastric banding devices is presented. One cohort of this study includes 40 subjects who have had a band placed by laparotomy. A second cohort includes 22 subjects who have had a newly designed adjustable silicone gastric band (ASGB) placed by laparoscopic or open technique. The goal of this investigation is to evaluate the achievement of sustained weight loss without the need for re-operation. Because of the frequent need for re-operation to correct life-threatening complications or ineffectiveness of ASGB devices, present clinical data indicate that improvements to the implantable system and the operative technique need to be made and verified by long-term study. At this point in development, ASGB remains an investigative procedure that has not fulfilled the scientific requirements of an accepted surgical treatment for severe obesity.