The aim of the study was to analyze the clinicopathological characteristics and survival outcomes in Siewert type II and Siewert type III tumors. The clinicopathological characteristics and survival outcomes were analyzed in patients diagnosed with Siewert II/III tumors, who underwent transabdominal gastrectomy from Jan 2006 to Dec 2010. A total of 321 patients diagnosed with Siewert II/III tumors who underwent gastrectomy were enrolled in this study. Siewert III tumors are larger and have a higher proportion of Borrmann 3-4 types than Siewert II tumors (p < 0.05). For Siewert II and the Siewert III tumors, the 3-year overall survival rate was 59.1 versus 57.1 %, respectively, and the median survival time was 46.0 (31.5-60.5) months versus 46.0 (31.3-60.7) months, respectively. Positive proximal resection margin, large tumor size, Borrmann 3-4 types, poor or undifferentiated degree and advanced T stages and N stages were found to be poor prognostic risk factors for the overall survival outcomes by univariate analysis. Multivariate analysis revealed that the differentiation degree (poor and undifferentiated) and advanced T and N stages were independent prognostic factors for poor overall survival. Siewert III tumors were larger and had a lower differentiation degree than Siewert II tumors, whereas there was no difference in the survival outcomes.