Background: The most common and significant cause for morbidity following emergency appendicectomy is surgical wound infection. There are conflicting reports regarding the optimal duration of antibiotic prophylaxis in nonperforated appendicitis. The efficacy of prolonged prophylactic antibiotic treatment in preventing wound infection for nonperforated appendicitis is poorly defined. Objective: A prospective randomized study was carried out to compare the efficacy of single dose cefazolin with three doses of cefazolin in reducing the incidence of postoperative wound infection for patients with nonperforated acute appendicitis. Methods: One hundred patients with a clinical diagnosis of appendicitis were randomized into two groups. Group 1 received single intravenous dose of 1gm cefazolin at induction of anaesthesia and group 2 received two further doses of cefazolin following surgery. Postoperative wound infection was the primary endpoint. Results: The two groups were similar with regard to demographic data, pathologic condition of the appendix and duration of hospital stay. The postoperative wound infection rate was not significantly different among the two groups, 11% in group 1 and 9% group 2 (p =0.986). Conclusions: Single-dose cefazolin is equally effective to multiple-dose cefazolin in preventing postoperative wound infection in patients undergoing open appendicectomy for nonperforated acute appendicitis. However, because of the greater convenience and economic implications, single pre-operative dose of cefazolin is the choice of prophylaxis for nonperforated appendicitis.