Background: Venous thromboembolism(VTE) is common after pneumonectomy for malignancy and predicts poor survival. Routine screening for VTE with noninvasive tests has low sensitivity and specificity. Biopsy of lung has a place in establishing the nature and severity of the vascular alterations. In this study, we investigated the incidence, clinical and pathological characteristics of thrombosis in excised specimens after pneumonectomy, and its association with survival rate in patients with non-small cell lung cancer (NSCLC). Methods: The studied population consisted 94 consecutive patients after pneumonectomy for NSCLC in Beijing Chao-Yang Hospital, The excised tissue specimens were stained by haematoxylin & eosin staining (HE) to observe thrombosis events. All the patients were followed up for 2 years. The survival data was analyzed by Kaplan-Meier analysis. Results: Overall thrombosis events occurred in 56 (59.6%) of 94 NSCLC cases, pulmonary arterial thrombosis was found in 24 cases, and pulmonary venous thrombosis was found in 32 cases. Furthermore, 30 of 56 cases with thrombosis were accompanied by tumor emboli or tumor vascular infiltrating. Thrombosis risk was associated with cancer grade (P = 0.005). Kaplan-Meier analysis showed that patients with thrombosis had lower survival rate than those without thrombosis (P = 0.025). Conclusions: The incidence of thrombosis in excised tissue after pneumonectomy was high in patients with NSCLC, and it may be a marker of poor outcome. (C) 2015 Elsevier Ltd. All rights reserved.