The invention relates to a device (1) for tying a knot, said device comprising a thread (10) having a functional end (12) and a pull end (13). According to the invention, a main body (2) is provided and the thread (10) is laid around the outer surface (3) of said main body in the form of a prepared, still open knot (11), such that as a result of pulling on the pull end (13), the thread slides along the lateral surface (3) and forms a closed knot.