A mechanism for installing a door or other similar closure device with rotary and translational motion, of the type comprising the following elements to be associated with a leaf - first pivoting means, which form a first vertical axis for the pivoting of the leaf, in a central region thereof, to means for translational motion arranged so as to slide in a corresponding guide associated with the upper stringer of the frame of the door; - second pivoting means, whose axis is parallel with respect to the axis of said first pivoting means, for the articulation of two arms (16, 17), a first upper arm and a second lower arm, which are both pivoted by means of a first end (21, 22) thereof to the frame of the door proximate to a jamb of the frame so as to form a second rotation axis, - third pivoting means, which are formed by the second ends (23, 24) of said arms (16, 17), which are hinged to the leaf so as to form a third rotation axis that passes through the leaf parallel to said first and second axes and in an intermediate position between said two first and second axes when the leaf is in the closed configuration, said second pivoting means comprising a pivot arranged in a compartment formed within the jamb, said pivot joining the first ends (21, 22) of said arms (16, 17) and causing their joint rotation, said mechanism further comprising means for setting and adjusting the distance of the third rotation axis from the second rotation axis, characterized in that said means for setting and adjusting the distance of the third rotation axis from the second rotation axis being constituted by a flat block, which supports a third pivot, said flat block being arranged so as to perform a translational motion at the end of the second arm, thanks to a through opening which is contoured to be crossed by said end of the lower arm, and the position of the block being defined by means of a fixing grub screw, to be screwed into a corresponding threaded hole provided in one side of the block until it affects the through opening and abuts within it against the end of the second arm. - first pivoting means, which form a first vertical axis for the pivoting of the leaf, in a central region thereof, to means for translational motion arranged so as to slide in a corresponding guide associated with the upper stringer of the frame of the door; - second pivoting means, whose axis is parallel with respect to the axis of said first pivoting means, for the articulation of two arms (16, 17), a first upper arm and a second lower arm, which are both pivoted by means of a first end (21, 22) thereof to the frame of the door proximate to a jamb of the frame so as to form a second rotation axis, - third pivoting means, which are formed by the second ends (23, 24) of said arms (16, 17), which are hinged to the leaf so as to form a third rotation axis that passes through the leaf parallel to said first and second axes and in an intermediate position between said two first and second axes when the leaf is in the closed configuration, said second pivoting means comprising a pivot arranged in a compartment formed within the jamb, said pivot joining the first ends (21, 22) of said arms (16, 17) and causing their joint rotation,