Abstract: In the present invention, there is provided a tree processor attachment for optionally mounting transversely on a forward section of the log carrying portion of a log porter, so that a log porter may advantageously be used to process felled trees, and to carry logs therefrom to a forest road. The tree processor attachment comprises a tree trunk holding and severing portion and a tree trunk advancing and delimbing portion having a pair of tree trunk delimbing jaws. The tree trunk advancing and delimbing portion is telescopically mounted in the tree trunk holding and severing portion, and is movable back and forth a pair of tree trunk holding jaws. The tree trunk advancing and delimbing portion is timely operable in association with the tree trunk holding jaws for moving a tree trunk in successive unidirectional movements toward a tree trunk severing saw. The tree holding and severing portion of the tree processor attachment is rotatable within a sway angle about a swivel member on a mounting base thereof.