A 2-center pilot study compared clinical and laboratory outcomes in 40 patients with psoriatic arthritis before and after treatment for 8 to 24 weeks with the vitamin A derivative, etretinate. The number of tender joints fell from 22.0 +/- 8.75 before treatment to 11.44 +/- 8.50 after treatment (p = .000). The duration of morning stiffness was 101.95 +/- 62.45 min before therapy and 44.53 +/- 82.10 min after treatment (p = 0.0004). Similar highly clinically and statistically significant improvement was seen in all clinical outcome measures and in the erythrocyte sedimentation rate. Primarily mucocutaneous side effects were seen in 39/40 patients and resulted in treatment termination before 24 weeks in 9 patients.