AbstractPlatelet‐derived growth factor (PDGF) in the resected pulmonary adenocarcinoma tissue of 88 patients was detected immunohistochemically by the avidin‐biotin‐peroxidase technique to determine whether or not it is a prognostic parameter. The 88 patients were divided into PDGF (‐) and PDGF (+) groups according to the stainability of the factor. The PDGF (‐) group included 39 patients and the PDGF (+) group 49. The 5‐year survival rate was 53% for the PDGF (‐) group and 17% for the PDGF (+) group (P<0.01). These findings indicate that the stainability of PDGF can be a prognostic parameter for pulmonary adenocarcinoma. © 1995 W