The disclosure describes an endoscopic delivery system that includes an endoscope and a tissue-receiving member. The tissue-receiving member includes an opening to receive the distal end of the endoscope. The tissue-receiving member also defines a tissue-receiving space that receives tissue when vacuum pressure is applied to the space through the endoscope. A tool and/or material may be delivered to the tissue drawn into the tissue-receiving space. The tissue-receiving member may be cap-like, and only receive the distal end of the endoscope, or include an overtube that receives a substantial portion of the endoscope. The system may be used to, for example, deliver tissue bulking devices to a location proximate to the lower esophageal sphincter (LES) for treatment of gastroesophageal reflux disease (GERD).