Abstract: A tree-cutting device for lumbering machines comprises a holder structure capable of being brought into contact with a tree to be felled, a swingable chain saw operable to saw only partially through the trunk of said tree, and a movable sharp-edged cutting blade operable to subsequently cut off the remainder of the tree trunk left by the chain saw. In order to assure most favorable operating conditions and minimize damage to the wood in the root end of the tree trunk, the chain saw is pivotally mounted in a sheltering structure forming a swingable gripping arm operable to press the tree trunk against a rigid part of the holder structure, while the cutting blade is projectable along a straight path in a plane forming an oblique angle to the plane of swing of the chain saw from a sheltered inoperative position within said rigid part of the holder structure.