In a double-blind, placebo-controlled study the efficacy and safety of topical ketorolac tromethamine were assessed in the reduction of inflammation and pain due to ankle sprain. Ketorolac 2% gel was compared with etofenamate and placebo (ketorolac vehicle) in a 15-day study. Patients attended for visits on days 1 (admission), 2, 3, 4, 8, and 15 of the study. Measurements of efficacy were ankle volume, pain measured on visual analogue scales (VAS) and verbal rating of pain. Safety was assessed by volunteered adverse events and vital signs. A total of 37 patients was admitted to the study of whom 13 received ketorolac, 12 placebo, and 12 etofenamate. One patient receiving ketorolac was lost to follow-up on day 15 owing to an unrelated accident. The remaining 36 patients completed the study. Ketorolac was significantly better than placebo in reducing the volume of the injured ankle based on the maximum, the area under the curve, and the day 15 percentage changes in ankle volume. Results for etofenamate were similar to those for ketorolac for all three variables and there were no significant differences between the active treatments. Reductions in VAS pain at rest were more marked in the ketorolac group than either of the other groups at all visits. On day 4 the differences between ketorolac and each of the other groups were statistically significant. Reductions in VAS pain on movement were also greatest for the ketorolac group at all visits. The differences between ketorolac and each of the other groups achieved statistical significance on days 4 and 8, but were marginal in terms of significance on day 2.(ABSTRACT TRUNCATED AT 250 WORDS)