A device (100) for injecting or infusing fluids into trees comprising a tool (1) for insertion into trees, comprising a first proximal end (3), a second distal end (4) and a body (2) that is extends axially between said first (3) and second (4) end, said second distal end (4) of the cuneiform type, provided with a linear edge (6) to favor the insertion of said tool (1) in the trunk of a shaft (A), said edge (6) extending linearly in an almost orthogonal direction to a longitudinal axis (Y) of said body (2), said body (2) having a cross section (10) having a shape biconvex lenticular； a passage (11) for injecting or infusing a fluid in said shaft (A), created in said body (2), said passage (11) extending from said first proximal end (3), and at least one opening (12a, b ) created along said body (2)； the device (100) also comprising a firing pin (20) comprising a housing (21) for said first proximal end (3) and a free head (22) capable of receiving a pushing or pulling force to favor the insertion of said tool (1) in the trunk of a tree (A) or to extract said tool (1) from said tree (A), respectively, said / or housing (21) and head (22) being almost aligned with said axis longitudinal (Y), said device (100) comprising a waterproof sealed gasket (26), installed in the tool (1) and arranged aligned with the housing (21) of the firing pin (20), characterized in that said waterproof sealed gasket (26 ) is placed between the bark of the tree and said first end (3) when the body (2) of the tool (1) is completely inserted into the tree.Un dispositivo (100) para inyectar o infundir fluidos en árboles que comprende una herramienta (1) para su inserción en árboles, que comprende un primer extremo proximal (3), un segundo extremo distal (4) y un cuerpo (2) que se extiende axialmente entre dicho primer (3) y segundo (4) extremo, siendo dicho segundo extremo distal (4) del tipo cuneiforme, provisto de un borde lineal (6) para favorecer la inserción de dicha herramienta (1) en el
