Machine for sealing plastic profiled elements, comprising: - at least a base frame; - at least a pair of retention members (7, 8), adapted to retain respective plastic profiled elements having respective: - a first main face and a second main face, which are the faces of said profiled elements which substantially lie on the plane of the door/window when a door/window/wall frame is assembled; - a first lateral face, which is the face of said profiled elements which substantially lies on the outer perimeter of the door/window when a door/window/wall frame is assembled; - a second lateral face, which is the face of said profiled elements which substantially lies on the inner perimeter of the door/window when a door/window/wall frame is assembled; - areas to seal with a first main edge, a second main edge, a first lateral edge and a second lateral edge, which correspond to the joining margins of said areas to seal with said first main face, said second main face, said first lateral face and said second lateral face, respectively; - at least a heat-sealing element with heated plate, mounted on said base frame and having two faces opposite one another on which said areas to seal are placeable in contact; - sliding means (9, 10) of said retention members (7, 8), which are placed between said base frame and said retention members (7, 8) and are adapted to shift said profiled elements between a position of reciprocal moving away and a position of reciprocal moving close in which said heated areas to seal are joined together; - removing means (13, 14) mounted on said base frame and adapted to: - remove material from said areas to seal at least at said first lateral edge; - achieve at least a lateral groove on said first lateral edge; characterized by the fact that said machine comprises lateral containment means (23, 24), which are mounted on said base frame and adapted to abut on said areas to seal at said first lateral edge for the containment of a lateral sealing bead, wherein said lateral containment means (23, 24) comprise at least a V-shaped element having two sides arranged in a V pattern which are adapted to abut on at least a portion of respective first lateral faces of said profiled elements, said V-shaped element defining, in cooperation with said lateral groove, a lateral containment compartment of said lateral sealing bead. - at least a base frame; - at least a pair of retention members (7, 8), adapted to retain respective plastic profiled elements having respective: - a first main face and a second main face, which are the faces of said profiled elements which substantially lie on the plane of the door/window when a door/window/wall frame is assembled; - a first lateral face, which is the face of said profiled elements which substantially lies on the outer perimeter of the door/window when a door/window/wall frame is assembled; - a second lateral face, which is the face of said profiled elements which substantially lies on the inner perimeter of the door/window when a door/window/wall frame is assembled; - areas to seal with a first main edge, a second main edge, a first lateral edge and a second lateral edge, which correspond to the joining margins of said areas to seal with said first main face, said second main face, said first lateral face and said second lateral face, respectively; - a first main face and a second main face, which are the faces of said profiled elements which substantially lie on the plane of the door/window when a door/window/wall frame is assembled; - a first lateral face, which is the face of said profiled elements which substantially lies on the outer perimeter of the door/window when a door/window/wall frame is assembled; - a second lateral face, which is the face of said profiled elements which substantially lies on the inner perimeter of the door/window when a door/window/wall frame is assembled; - areas to seal with a first main edge, a second main edge, a first lateral edge and a second lateral edge, which correspond to the joining margins of said areas to seal with said first main face, said second main face, said first lateral face and said second lateral face, respectively; - at least a heat-sealing element with heated plate, mounted on said base frame and having two faces opposite one another on which said areas to seal are placeable in contact; - sliding means (9, 10) of said retention members (7, 8), which are placed between said base frame and said retention members (7, 8) and are adapted to shift said profiled elements between a position of reciprocal moving away and a position of reciprocal moving close in which said heated areas to seal are joined together; - removing means (13, 14) mounted on said base frame and adapted to: - remove material from said areas to seal at least at said first lateral edge; - achieve at least a lateral groove on said first lateral edge; - remove material from said areas to seal at least at said first lateral edge; - achieve at least a lateral groove on said first lateral edge;