SummaryA double-blind randomized trial was carried out in 161 primiparous women suffering from moderate to severe post-episiotomy pain to compare the analgesic efficacy of single doses of diflunisal (125 mg, 250 mg, or 500 mg), aspirin (600 mg), and placebo. The results of pain rating assessments made before and at hourly intervals after drug administration showed that both the active drugs were more effective than placebo and produced similar pain relief over the first 4 hours. The analgesic efficacy of aspirin tailed off after 4 hours but pain relief with 500 mg diflunisal was still evident after 8 hours. Over 65% of patients in the diflunisal group had effective relief of pain at 8 hours whereas there was no significant difference between the aspirin and placebo-treated groups by the seventh and eighth hour.