We developed two types of fine sialendoscope, which could be introduced to the submandibular duct through the opening of sublingual caruncula. One is a sialendoscope of 1.1-mm outer-diameter (POLYDIAGNOST GmbH, Germany) with 6000-pixels optic fibers, and it has a working channel to insert a basket forceps and an irrigation channel. The other is a sialendoscope of 1.2-mm outer-diameter (FiberTech Co., Ltd., Japan) with 1600-pixels optic fibers and a working channel. Using these newly developed sialendoscopy systems and a 1.9F basket forceps (Boston Scientific Corporation, USA), we could successfully remove a sialolith of the submandibular gland of a 9-year-old girl.