Abstract: Postoperative anal pain is one of the main adverse effects of surgical treatment of benign anorectal diseases and remains a distressing problem, for both patients and physicians. Postoperative pain control is important yet it remains an unresolved issue which causes patient dissatisfaction and negatively impact quality of life. This review article studied the analgesic effect of topical and oral metronidazole after benign anorectal surgery. Seven studies used oral metronidazole and six used topical metronidazole. The studies showed that post operative pain score of patients who had metronidazole by either route was significantly less than those in comparison groups. The pain score decreased at all the time points for both oral and topical metronidazole. Overall, the analgesic effect of oral metronidazole was inconsistent among published studies. When topical and oral metronidazole were compared the post operative pain score and analgesic consumption were lower in topical metronidazole than the oral group.