A bicycle bar end attachment includes a main body, a shoe, a compression member, a rotation member, a transmission structure and a fixing structure. The main body is insertable into a bicycle handlebar, and includes a first threaded portion. The shoe is located between an inner surface of the handlebar and the main body. The compression member includes a second threaded portion engaged with the first threaded portion and a first pressing surface contacting one end of the shoe. The rotation member includes an exposed portion accessible from outside the handlebar and a second pressing surface contacting the other end of the shoe. The transmission structure transmits rotation of the rotation member to the compression member. The fixing structure holds the shoe between the compression member and the rotation member, and moves the shoe in a radial direction of the handlebar to fix the main body to the handlebar.