Interleukin (IL)-1 beta has been reported to be a marker of shorter survival in gastric and colorectal adenocarcinoma. In the present study, we examined the potential role and prognostic value of IL-1 beta in esophageal squamous cell carcinoma (SCC). Human esophageal SCC cell line, CE81T, was selected for cellular and animal experiments, in which biological changes after experimental manipulation of IL-1 beta signaling were explored, including tumor growth, invasion capacity, and the sensitivity to treatment. Moreover, 147 esophageal SCC samples were analyzed using immunohistochemical staining to correlate the expression of IL-1 beta with clinical outcome. Our data revealed that IL-1 beta was significantly overexpressed both at mRNA and protein levels in cancer specimens compared to nonmalignant tissues. When IL-1 beta signaling was blocked, tumor growth, invasion ability, and treatment resistance were attenuated. Activation of NF-kappa B, increase of E2-EPF ubiquitin carrier protein and subsequent epithelial-mesenchymal transition might be the underlying mechanisms of the more aggressive tumor growth in IL-1 beta-positive esophageal cancer. The immunochemistry findings indicate that positivity staining of IL-1 beta correlated significantly with higher clinical stage, lower response rate to concurrent chemoradiotherapy (CCRT), and higher recurrence rate after curative treatment. Moreover, IL-1 beta was a significant predictor of survival in patients undergoing surgical intervention or definite CCRT. In conclusion, IL-1 beta is significantly linked to poor prognosis for patients with esophageal cancer and may be a promising molecular target for therapeutic intervention for esophageal SCC.