BackgroundNasopharyngeal carcinoma (NPC) is a common malignancy occurring in the head and neck. Identification of immune‐related methylated biomarkers might be helpful for NPC detection and prognostic evaluation.MethodsA co‐methylation network based on WGCNA was constructed to identify modules associated with NPC and immune cells. In combination with differentially expressed genes (DEGs) and immune‐related genes from ImmPort database, the candidate immune‐related methylated genes (IRMGs) were obtained.ResultsOur combined analysis identified 12 IRMGs. Among them, both the methylation and mRNA expression of CCL28, CSK, and PRKCB were correlated with the infiltration of B cells. CD1D, CR2, and GDF10 were favorable markers. Demethylation experiments validated that downregulation of GDF10, PRKCB, SLC40A1, and TGFBR3 in NPC resulted from promoter hypermethylation. Additionally, a diagnostic model was developed and exhibited high discriminative accuracy.ConclusionsThese results provided a group of immune‐related methylated biomarkers that may help with the diagnosis and prognosis of NPC.