Esophageal cancer (ESCA) is a lethal malignancy and is associated with the alterations of various genes and epigenetic modifications. The protein dpy-30 homolog (DPY30) is a core member of histone H3K4 methylation catalase and its dysfunction is associated with the occurrence and development of cancer. Therefore, the present study investigated the role of DPY30 in ESCA and evaluated the association between the expression of DPY30, the clinicopathological characteristics of ESCA and the tumor immune microenvironment. It conducted a comprehensive analysis of DPY30 in patients with ESCA using The Cancer Genome Atlas (TCGA) database and clinical tissue microarray specimens of ESCA. Immunohistochemistry was performed to assess the expression levels of DPY30 in tissues. Receiver operating curve analysis, Kaplan-Meier survival analysis and Cox regression analysis were performed to identify the diagnostic and prognostic value of DPY30. Gene Set Enrichment Analysis, protein-protein interaction network and Estimation of Stromal and Immune cells in Malignant Tumor tissues using the Expression data were used to screen DPY30-associated genes and evaluate the immune score of the TCGA samples. The results demonstrated that the expression of mRNA and protein levels of DPY30 were significantly upregulated in tumor tissues compared with normal tissue samples. The expression of DPY30 was closely associated with the poor prognosis of patients with ESCA. The present study also found that DPY30 expression and the pathological characteristics of ESCA were significantly correlated. Additionally, the expression of DPY30 demonstrated a significant positive correlation with various immune cells infiltration. The results suggested that DPY30 might influence tumor immune infiltration. In conclusion, the findings suggested that DPY30 might be a potential prognostic biomarker and an immunotherapeutic target in ESCA.