A composition for use in a pulmonary fibrosis treatment, comprising a vehicle comprising a retinoid as a targeted agent and a drug that controls the activity or growth of extracellular matrix producing cells in the lung, in which the retinoid has a skeleton in which four isoprenoid units are attached in a head-tail manner, in which the drug that controls the activity or growth of extracellular matrix producing cells in the lung is selected from the group consisting of: (i) an agent selected from the group consisting of (1) an siRNA, (2) a ribozyme, (3) an antisense nucleic acid and (4) a chimeric DNA / RNA polynucleotide, which directs molecules involved in the production or secretion of said molecules constituents of the extracellular matrix, wherein said molecule involved in the production or secretion of said molecules constituting the extracellular matrix is HSP 47, or a substance ia selected from the group consisting of (1) an siRNA, (2) a ribozyme and (3) an antisense nucleic acid, in which the substance suppresses the production and secretion of a component of the selected extracellular matrix of collagen, proteglucan, tenascin, fibronectin, thrombospondin, osteonectin and elastin and (ii) a vector that expresses said siRNA, said ribozyme, said antisense nucleic acid and / or said chimeric DNA / RNA polynucleotide.Una composición para su uso en un tratamiento de fibrosis pulmonar, que comprende un vehículo que comprende un retinoide como agente dirigido y un fármaco que controla la actividad o el crecimiento de células productoras de matriz extracelular en el pulmón, en el que el retinoide tiene un esqueleto en el que cuatro unidades de isoprenoide están unidas de un modo cabeza-cola, en la que el fármaco que controla la actividad o el crecimiento de las células productoras de matriz extracelular en el pulmón se selecciona del grupo que consiste en: (i) un agente seleccionado del grupo que consiste en (1) un ARNip, (2) una ribozima, (3) un ácido nucleico anti