AimThe aim of the study was to evaluate the addition of serum sodium to the model for end-stage liver disease (MELD) score as a prognostic factor for survival in patients with decompensated liver cirrhosis. Patients and methods Sixty patients with posthepatitis C virus decompensated liver disease were included. They were Child class B or C according to the Child-Pugh classification. The following investigations were performed for all patients: complete blood count, liver function tests, serum sodium, and abdominal ultrasonography. MELD score and MELD-Na were calculated for all patients. All patients were followed up after 3 months clinically and by laboratory analysis. Results A significant increase in class C patients after 3 months (Po0.05) was detected. There was no statistical significant difference between MELD-Na and MELD scores, either at onset or after 3 months (P40.05). MELD score was more reliable to predict mortality (Po0.05). For prediction of mortality, the best cutoff value for MELD score was 20 with a sensitivity of 71% and specificity of 75%, whereas the best cutoff value for MELD-Na was 30 with a sensitivity of 70% and specificity of 58%. There was a statistically significant difference between living and dead patients with respect to the distribution of MELD score and Child classification, whereas no statistically significant difference between living and dead patients with respect to the distribution of MELD-Na was found. Conclusion MELD score is more reliable at prediction of mortality than MELD-Na, and the best cutoff value for MELD score is 20, whereas the best cutoff value for MELD-Na is 30. The study could not elicit a value of adding serum sodium to the MELD scoring system. Keywords:decompensated liver disease, model for end-stage liver disease, model for end-stage liver disease-Na, survival Receiver operating characteristic (ROC) curve to define the best cutoff of model for end-stage liver disease (MELD)-Na and MELD scores to predict mortality.'Serum sodium' as a variable in the MELD Montasser et al. 33