A cover adapted to be received on the distal end of a medical probe or instrument such as an endoscope in such a manner as to not require the application of a retainer. The cover is constructed of two panel members secured one to the other along their respective sides. A throat is defined proximate the first end and is adapted to closely receive the distal end of the medical probe. The first ends of each of the panels are folded over to define a double thickness of material. The first panel member first end extends beyond the second panel member first end to define an extended portion, which provides a mechanism whereby the distal end of the medical probe is easily inserted into the first end of the cover. The second end of the cover is inverted to assist in the application of the cover of the medical probe.