ABSTRACT Background: A serious problem for cirrhotic individuals is spontaneous bacterial peritonitis (SBP). Clinical significance of SBP's C-reactive protein (CRP) as well as neutrophil-to-lymphocyte ratio (NLR) have been discovered using varying threshold levels. Objective: The aim of the current work was to assess the validity of diagnostic paracentesis with the use of combined blood NLR and CRP as a non-invasive predictor for early diagnosis of SBP. Patients and Methods: This case control study included a total of 60 cirrhotic decompensated patients, admitted at Department of Tropical Medicine, Zagazig University Hospitals. Patients were categorized into two groups (30 each) according to neutrophil count in Ascitic fluid; Group I with SBP and Group II free from SBP. Both NLR and CRP were assessed among all subjects. Results: NLR was statistically significant higher in SBP group. A cut-off value of blood NLR >2.9 on ROC curve had a specificity of 88% as well as sensitivity of 95% for SBP diagnosis in cirrhotic patients. CRP level differed significantly among cirrhotic patients diagnosed with SBP. A cut-off >15 mg/L had a sensitivity and specificity of 85% and 90 % respectively in diagnosing SBP in cirrhotic patients. Combination NLR and CRP had a cut-off >22.6 mg/L, had a sensitivity and specificity of 86%, 91 % respectively in SBP diagnosis among cirrhotic patients. Conclusions: Combined NLR and CRP with cut of >2.9, and >15 mg/dl respectively could be used as a novel, non invasive predictor for SBP diagnosis.