An intravenous treatment device including a system (1； 2) for administering at least one treatment dose, whose administration system (1； 2) comprises a treatment administration cable element (1), which is flexible, that it has a distal end part (10) apt to be inserted, at least over part of its length, longitudinally in a vein (V), and that allows to administer in a vein (V) at least one treatment dose in the region of the end of said distal end part (10), the endovenous treatment device further comprising an actuation system (4) that allows the treatment dose administration cable element (1) to be actuated in at least one first direction (R) drive, characterized in that it further comprises a guide (3) that is flexible in all or part of its length, that includes a proximal end part (31) and a distal end part (30), and that allows guiding the cable ( 1) administering treatment doses, in a portion of its length, with a proximal end part (11), and on the opposite side, a distal end part (10) of the cable dose administration cable (1) element treatment, which are not guided by the guide (3), and because it also comprises a maintenance system (5) that allows the distal end part (30) of the guide (3) to be temporarily maintained with respect to the body of a patient, near the insertion zone (7) of the treatment dose delivery cable element (1), the treatment dose delivery cable element (1) being able to slide in the direction of its length with respect to the guide (3), to allow longitudinal insertion into a vein (V) of the distal end part (10) of the treatment dose delivery cable element (1) at least part of its length when the distal end part (30) of the guide (3) is maintained in relation to the body of a patient by means of the maintenance system (5) and locking means (6), which allow axially locking the proximal end part (31) of the guide (3), at least in the direction (R) of actuation of the element cable (1) for administration of treatment doses.Un dispositivo de t
