Clinicopathological variables that might have an effect on prognosis were analyzed in 98 samples of resectable peripheral lung adenocarcinoma. Pathological stage (stage I v stage II, III, or IV; P < .001), degree of central fibrosis (grade 1 or 2 v grade 3 or 4; P < .01), and histological grade (well differentiated v moderately or poorly differentiated; P < .05) were shown to be prognostic factors, whereas any other variable, including patient age at diagnosis, sex, cigarette smoking habits, and tumor histological subtype and cytological type, showed no meaningful correlation with patient length of survival. The distribution pattern of the basement membranes (BMs) was significantly associated with pathological stage (intact v disrupted or absent; P < .001). It was noteworthy that in stage I samples a significant relationship between the distribution pattern of the BMs and patient length of survival was found (intact v disrupted or absent; P < .001), although such a relationship could not be detected when analyzed in samples from the other pathological stages. The distribution pattern of the BMs also was correlated with the presence or absence of lymph node metastasis but not with its extension. There were no meaningful relationships between the distribution pattern of the BMs and any other clinicopathological variables, including degree of central fibrosis, histological grade, etc. The distribution pattern of the BMs in peripheral lung adenocarcinomas might be useful for postoperative therapeutic strategy and could serve as an important prognostic indicator for stage I lesions.