Background Emerging evidences suggest that lymph node ratio (LNR), the number of metastatic lymph node (LN) to the total number of dissected lymph nodes (NDLN), may predict survival in multiple types of solid tumor. However, the prognostic role of LNR in adenocarcinoma of the esophagogastric junction (AEG) remains uninvestigated. The study is intended to determine the prognostic value of LNR in the patients with Siewert type II AEG. Methods A total of 342 patients with Siewert type II AEG who underwent R0 resection were enrolled in this study. The optimal cutoff of LNR was strati ed into tertiles using X-tile software. The log-rank test was used to evaluate the survival differences, and multivariate Cox regression analysis were performed to determine the independent prognostic variables. Results The optimal cutoff of LNR were classi ed as LNR = 0, LNR between 0.01 and 0.40 and LNR > 0.41. Patients with high LNR had a shorter 5-and 10-year disease-speci c survival (DSS) rate (8.5%, 1.4%) compared with those with moderate LNR (20.4%, 4.9%) and low LNR (58.0%, 27.5%) (P < 0.001). Multivariate Cox regression analysis indicated that LNR was an independent factor for DSS after adjusting for confounding variables (P < 0.05). Furthermore, after strati cation by NDLN between NDLN < 15 group and NDLN ≥ 15 group, the LNR remained a signi cant predictor for DSS (P < 0.05). Conclusions LNR is an independent predictor for DSS in patients with Siewert type II AEG regardless of NDLN. Patients with higher LNR have signi cantly shorter DSS.