In 4 double-blind, randomized, stratified, parallel group studies, single oral doses of fluproquazone (75 to 200 mg), a new nonsteroidal anti-inflammatory analgesic, were compared with aspirin (1,000 mg) and placebo in a total of 672 hospitalized patients with moderate or severe pain following episiotomy or other surgical interventions. A dose-dependent effect of fluproquazone which was highly significantly superior to placebo and which resembled the effect of aspirin with respect to onset, degree, and duration was noted in all studies. Fluproquazone, 100 to 150 mg, was found to be approximately equiactive to 1,000 mg of aspirin and better tolerated.