A door or window, comprising a liftable sliding leaf and a lifting system for lifting the liftable sliding leaf, in such a way that said liftable sliding leaf is slidable in a horizontal direction, the lifting system comprising: a lifting mechanism, connected to the liftable sliding leaf, said lifting mechanism being movable between a first configuration and a second configuration, respectively associated with a first condition in which the liftable sliding leaf rests on the ground and the sliding thereof is prevented and a second condition in which sliding of the liftable sliding leaf is possible, by respectively lowering and lifting said liftable sliding leaf by means of the movement of said lifting mechanism; a control member which is connected to and acts on the lifting mechanism in such a way as to switch said lifting mechanism between said two configurations, said control member being located in a fixed frame of the door or window comprising the liftable sliding leaf; characterized in that the lifting mechanism is connected to a top part of the liftable sliding leaf; wherein the lifting mechanism comprises a tie-rod connected to the control member and connected to the top part of the liftable sliding leaf, said tie-rod being able to exert a thrusting and/or pulling force on said top part so as to cause the lowering or lifting of the liftable sliding leaf; wherein said tie-rod is movable by means of a slide displaced by the control member, said slide being connected to the lifting mechanism so as to be movable between said first and second configurations for lifting and lowering the liftable sliding leaf; wherein the tie-rod is connected to the sliding leaf by means of a linkage able to exert a lifting or lowering torque on the liftable sliding leaf, pivoting about a pin fixed with respect to the fixed frame of the door or window; and wherein the linkage comprises a bracket pivoting about the fixed pin and having one end connected to the tie-rod and one end connected to a guide which is connected to to the top part of the liftable sliding leaf, so as to allow sliding of said liftable sliding leaf, forming an articulated connection so that, when the tie-rod is pulled, the movement can be transmitted to the guide by means of pivoting of the bracket about the fixed pin so as to lift the guide. a lifting mechanism, connected to the liftable sliding leaf, said lifting mechanism being movable between a first configuration and a second configuration, respectively associated with a first condition in which the liftable sliding leaf rests on the ground and the sliding thereof is prevented and a second condition in which sliding of the liftable sliding leaf is possible, by respectively lowering and lifting said liftable sliding leaf by means of the movement of said lifting mechanism; a control member which is connected to and acts on the lifting mechanism in such a way as to switch said lifting mechanism between said two configurations, said control member being located in a fixed frame of the door or window comprising the liftable sliding leaf; characterized in that the lifting mechanism is connected to a top part of the liftable sliding leaf; wherein the lifting mechanism comprises a tie-rod connected to the control member and connected to the top part of the liftable sliding leaf, said tie-rod being able to exert a thrusting and/or pulling force on said top part so as to cause the lowering or lifting of the liftable sliding leaf; wherein said tie-rod is movable by means of a slide displaced by the control member, said slide being connected to the lifting mechanism so as to be movable between said first and second configurations for lifting and lowering the liftable sliding leaf; wherein the tie-rod is connected to the sliding leaf by means of a linkage able to exert a lifting or lowering torque on the liftable sliding leaf, pivoting about a pin fixed with respect to the fixed frame of the door or window; and wherein the linkage comprises a bracket pivoting about the fixed pin and having one end connected to the tie-rod and one end connected to a guide which is connected to to the top part of the liftable sliding leaf, so as to allow sliding of said liftable sliding leaf, forming an articulated connection so that, when the tie-rod is pulled, the movement can be transmitted to the guide by means of pivoting of the bracket about the fixed pin so as to lift the guide.