M30 and M65 are circulating fragments of cytokeratin 18 released during apoptotic cell death and regarded as markers of cell death in patients with various tumor types. Our aim was to investigate the clinical and prognostic significance of the serum M30 and M65 concentrations in patients with advanced nasopharyngeal carcinoma. Thirty-two patients with nasopharyngeal cancer and 32 control subjects were investigated. Serum samples were obtained on first admission before any treatment was initiated. Serum M30 and M65 concentrations were measured by quantitative enzyme-linked immunosorbent assay. Median serum M30 (181.5 vs. 45.5 U/L, p < 0.001) and M65 (384.2 vs. 179.1 U/L, p < 0.001) concentrations were significantly higher in patients with advanced nasopharyngeal carcinomas than in controls. receiver operating characteristic (ROC) analysis showed that a cutoff for M30 of 225 U/L had a sensitivity of 62.5 % and a specificity of 73.9 % (area under the curve (AUC) = 0.592, 95 % confidence interval (CI) 35.3-83.2, p = 0.44), while a cutoff for M65 of 423.4 U/L had a sensitivity of 75.1 % and a specificity of 65.6 % (AUC = 0.562, 95 % CI 36.0-76.5, p = 0.60). However, serum M30 and M65 were not important prognostic factors for progression-free survival. There were no statistically significant correlations between serum M30 and M65 concentrations and clinicodemographical variables. Serum M30 and M65 concentrations were found to have a diagnostic value in nasopharyngeal cancer. However, neither M30 nor M65 serum levels played a prognostic role in the outcome in nasopharyngeal cancer patients.