Abstract : Acute appendicitis is one of the common surgical emergencies. This study analysed C- reactive protein as a diagnostic marker of acute appendicitis. To study the efficacy of C-reactive protein in the diagnosis of acute appendicitis. A prospective study done on patients coming to hospital with clinical diagnosis of acute appendicitis and underwent appendectomy. Operative and histopathological findings were compared and analyzed with C- reactive protein. A total of 100 patients were included in the study. CRP was more than 6mg/l in 89 patients, and out of 89 patients, 87 patients had histopathologically inflamed appendix and serum CRP estimation in diagnosis of acute appendicitis yield sensitivity of 90.6%, specificity of 50%, positive predictive value of 97.75% and negative predictive value of 18.2%. CRP was raised in patients with acute appendicitis and it aids as a marker for diagnosing acute appendicitis and decreasing the rate of negative appendectomy.