Twenty-five patients with symptomatic osteoarthritis (OA) of the knee were treated topically for one week with either 10% trolamine salicylate cream or placebo cream in a randomized double-blind crossover study. No significant difference was found in subjective or objective measures of pain relief between the treatment and control groups. Eight patients preferred "active" test cream, six preferred placebo, and 11 had no preference. No side effects were reported. Topically applied 10% trolamine salicylate cream did not relieve the pain of OA of the knee any more than did placebo.