Endoscope treatment tool

An endoscope treatment tool includes: a sheath; a clip unit; a biasing member arranged between a distal end part of the sheath and the clip unit; and a first rotation preventing part capable of preventing the clip unit from rotating relative to the distal end part of the sheath about a longitudinal axis. The clip unit includes: a clip body; a holding tube; and a second rotation preventing part capable of preventing the clip body from rotating relative to the holding tubes about the longitudinal axis. The biasing member biases the holding tube so as to separate from the distal end part of the sheath. When a proximal end part of the holding tube comes into contact with the distal end part of the sheath against the biasing force of the biasing member, the first rotation preventing part prevents the relative rotation of the clip unit.