Background: Peritonitis is classified as primary, secondary and tertiary. In primary peritonitis and continuous ambulatory peritoneal dialysis-associated peritonitis, the source of the infection is not due a breach in the gastrointestinal tract and usually caused by a single organism. Secondary peritonitis ensues, which may be localized and contained or diffuse carrying a high mortality in the absence of surgical intervention and appropriate antimicrobial therapy. In contrast, secondary peritonitis following perforation of the gastrointestinal tract or an infection originating in an intra-abdominal structure. Tertiary peritonitis is an ill-defined entity, which occurs despite adequate treatment of primary or secondary peritonitis.Methods: This is a prospective clinical study conducted on 140 consecutive patients who presented to the surgical department of RL Jalappa Hospital and Research Centre, Tamaka, Kolar with peritonitis secondary to hollow viscus perforation.Results: A total of 140 patients who presented with peritonitis secondary to hollow viscus perforation, admitted and treated in RL Jalappa Hospital and Research Centre attached to Sri Devaraj Urs Medical College, Kolar were studied during the period of December 2015 to June 2017.There was decrease in postoperative complications and hospital stay in Group B.Conclusions: In present study peritonitis is more common in men compared to women. The most common age group is in between 21-40 years in cases of peritonitis with the mean age of 37 years. Duodenal ulcer perforation is the commonest site of perforation. Escherichia coli is the most common organism isolated in the peritoneal fluid. usage of three antimicrobials (p<0.05) is beneficial in reduction in postoperative complications and hospital stay when compared to usage of two antimicrobials which is statistically significant.