Introduction: Acute appendicitis is one of the most common causes of urgent admission to the hospital.In appendicitis, elevated intra-luminal pressure and ischemic necrosis of mucosa causes tissue gangrene or perforation. This leads to cytotoxin facilitated progressive bacterial invasion or translocation into the hepatic parenchyma through portal system. This phenomenon interferes with the bilirubin excretion into the bile canaliculi. The rate of misdiagnosis of appendicitis and the rate of appendicular perforation has remained constant, inspite of increased use of ultrasonography, computed tomography scanning and laparoscopy. Among commonly used inammation markers of Acute appendicitis, bilirubin concentration is not well studied and thus is rarely applied. Every investigation that can contribute towards a diagnosis of appendicitis is valuable to the emergency general surgeon Aim: 1. To study the relationship between hyperbilirubinemia and acute appendicitis; and to evaluate its credibility as a diagnostic marker for acute appendicitis. 2. To evaluate whether elevated bilirubin levels have a predictive potential for the diagnosis of Appendicular perforation. Material and methods: The study was conducted in the Department of General Surgery, Navodaya Medical College & Research centre, Raichur during the period of January 2020 to December 2020.Patients admitted with clinical diagnosis of acute appendicitis or appendicular perforation under the Department of Surgery, Navodaya Medical College & Research centre, Raichur during the study period. A total of 100 patients with clinical diagnosis of acute appendicitis or appendicular perforation were studied. Results: .Normal bilirubin values were seen in 26% patients while, 74% had raised bilirubin levels (Hyperbilirubinemia). Of 81 patients with acute appendicitis, 71.6% had raised bilirubin levels, while 28.4% had normal levels. 19 patients were diagnosed as Appendicular perforation, 16 patients (84.21%) had raised bilirubin levels, while the remaining 03 patients (15.79%) had normal levels.Amongst the patients diagnosed with Acute appendicitis without perforation (n=81), 58 patients (71.6%) were found to have elevated bilirubin (>1.0 mg/dL) while only 23 patients (28.4%) had normal bilirubin levels (≤1.0 mg/dL). In patients diagnosed with Appendicular perforation (n=19), 16 patients (84.21%) had bilirubin elevated (>1.0 mg/dL), while only 3 patients (15.79%) had normal levels (>1.0 mg/dL). Thus, Hyperbilirubinemia was found in most of the patients diagnosed with acute appendicitis (71.6%) or Appendicular perforation (84.21%). Conclusion: The present study suggests- Serum bilirubin levels appears to be a promising new laboratory marker for diagnosing acute appendicitis, however diagnosis of appendicitis remains essentially still - clinical. Its level come out to be a credible aid in diagnosis of acute appendicitis and would be helpful investigation in decision making. Patients with clinical signs and symptoms of appendicitis and with hyperbilirubinemia higher than the normal range should be identied as having a higher probability of Appendicular perforation suggesting, serum bilirubin levels have a predictive potential for the diagnosis of Appendicular perforation.