Appendicectomy for non-perforated appendicitis has now become one of the most common abdominal operations.The rate of infections post open appendicectomy without antibiotic prophylaxis is still high. The use of antibiotics preoperatively has become necessary but the choice remains still controversial.Metronidazole being cheap and effective against anaerobic and gram-negative bacteria is considered a good option. In this study, 100 patients were selected and a comparative study was done between preoperative oral metronidazole administration and no prophylaxis and results were found that single oral metronidazole dosage for prophylaxis in cases of non-perforated appendicectomy was found very effective.