The present invention relates to a medical device for applying elastic ligatures to haemorrhoids commonly known as a haemorrhoid ligator.In particular, the present invention relates to an instrument (1) for ligating haemorrhoids, comprising a rod (3) provided with a handle (2) and having an end proximal to the operator and a distal end (9) adapted to receive one or more elastic rings (A1, A2). The distal end (9) and the proximal end of the rod (3) having respective openings (10, 11), a slidable member (4) being arranged on the outer surface of said rod (3), which is adapted to disengage upon a command said one or more elastic rings (A1, A2) from said distal end (9) of said rod (3), characterized in that actuating means (5) of said slidable member (4) are provided, comprising a mobile member (14), which can be screwed onto a threaded member (13) associated to said handle (2), so that the mobile member (14) can move along the axis (X) of said threaded member (13) following a manual command, said mobile member (14) being operatively connected with said slidable member (4) for advancing or retracting it.
