Background Postoperative death of thoracic endovascular aortic repair (TEVAR) occurred in patients with type B aortic dissection (TBAD). The prognostic value of anemia, an important problem during the perioperative period, is unknown. Methods According to predefined criteria, 184 TBAD patients underwent TEVAR were divided into two groups: non-anemia group and anemia group. Clinical data were compared between groups and multiple Cox proportional hazard regression analyses were performed to detect the risk factors of long-term mortality. Results After median 2.5 years follow-up, 21 patients died. Long-term mortality was significant higher in patients with anemia (23.9％ vs. 8.1％, P=0.006). Multivariate analyses showed that anemia was independently associated with increased risk of long-term mortality (HR=3.21, 95％CI: 1.31-7.89, P=0.011). The ROC curve showed that hemoglobin level had predictive role for long-term mortality (AUC=0.742, P＜0.001). The optimal cut -off was 130.2g/L, with sensitivity and specificity being 85.7％ and 52.0％, respectively. Conclusions Admission anemia was independently associated with increased risk of long-term post-TEAVR mortality in TBAD patients. Pre-TEAVR hemoglobin measure could be a risk assessment tool for TBAD patients undergoing TEAVR.