Prudent use of antibiotics gains more importance as increased antibiotic resistance along with a gradual recession in newly developed antibiotics is seen. It is aimed to show the importance of cultureantibiogram for detecting causative bacteria and antibiotic resistance profile for prudent antibiotic usage and empirical antibiotic coverage in pediatric and adult cases with peritonitis secondary to perforated appendicitis. This study includes a total of 58 patients who underwent surgery for perforated appendicitis and secondary peritonitis. Cultures-antibiogram obtained by suctioning of the peritoneal fluid or swabbing during the surgery of the patients having proliferation was evaluated. Out of total 35 pediatric cases, E. coli in 27 cases, E. coli and P. aeruginosa in 5 cases. In the 32 cases with E. coli cultured, antibiotic resistance was seen for Ampisilin-sulbactam (SAM) in 13 (36.1%) cases, ceftriaxone in 12 (33.3%) cases and Extended Spectrum Beta Lactamase (ESBL) in 10 (31.2%) cases. Out of total 23 adult cases, E. coli was cultured in 18 cases. Of the 18 cases with E. coli cultured, antibiotic resistance was seen for SAM in 10 (43.4%) cases, ceftriaxone in 9 (39.1%) cases and ESBL in 6 (33.3%) cases. It is believe that the evaluation of peritoneal culture results obtained during surgery will lead to a decrease in mortality and morbidity rates.