Background: Cirrhosis often leads to spontaneous bacterial peritonitis (SBP) development, a condition with a poor prognosis warranting liver transplantation. This study aimed to identify SBP frequency among cirrhotic patients with ascites and to determine its risk factors and predictors for inadequate antibiotic response. Methods: This analytical cross-sectional study involved 78 cirrhotic patients with ascites. Patients' workup included: at-admission evaluation (clinical, laboratory, and imaging), treatment and follow-up for SBP patients, and re-evaluation after 48 hours of antibiotics with treatment modification according to response. Results: Ascitic fluid (AF) examination and microbiological cultures revealed that 24.4% of admitted cirrhotic patients with ascites had one of SBP variants with diabetes mellitus, high random blood sugar, and low AF albumin as independent risk factors for SBP development.  26.3% of SBP patients experienced inadequate antibiotic response. Inadequate response group showed delayed antibiotic initiation and history of prior SBP, lower AF albumin, higher C-reactive protein (CRP), and positive culture. After 48-hours, inadequate response patients experienced fever, disturbed conscious level, and abdominal tenderness in 20%, 60%, and 80%, respectively compared to 7.14%,0%, and 14.3% in those with adequate response. Nonetheless, 48-hour investigations revealed little decrease or even increase in total leucocyte count (TLC) in the blood, CRP, blood urea, and serum creatinine in patients with inadequate response. Conclusion: Delayed antibiotic initiation, positive culture, and clinical suspicion together with non-significant decrease or even increase in TLC in the blood, CRP, blood urea, and serum creatinine 48-hours of antibiotic initiation are potential predictors for inadequate response. This helps identify who would benefit from a second paracentesis and minimize unnecessary invasive procedures.