Thirty-four patients with extensive psoriasis were treated in a double-blind parallel fashion with either acitretin plus bath PUVA (trimethylpsoralen bath + UVA) or etretinate plus bath PUVA. Each group consisted of 17 patients. The dose of retinoid was 40 mg/day during the 2-week monotherapy phase and subsequently 20 mg/day during the combination treatment. Bath PUVA was given three times a week starting with a UVA dose of 0.06 J/cm2. Remission (greater than 90% improvement) was achieved in all patients in 6-10 weeks. There were no significant differences in clinical response between the two groups; the mean +/- SD PASI score (psoriasis area and severity index) before treatment was 22.6 +/- 7.1 in the acitretin-PUVA group and 19.4 +/- 7.8 in the etretinate-PUVA group. The corresponding figures after treatment were 0.6 +/- 0.6 and 1.0 +/- 0.5, respectively. Side-effects related to retinoid treatment were frequent in both groups but they were usually mild and well-tolerated. There was only one case of diffuse alopecia after 8 weeks in the etretinate-PUVA group. Scaling of the palms and soles was seen in six patients in the acitretin-group but only in two patients in the etretinate-group. Triglycerides were elevated in about half of the patients in both groups. The present study shows that acitretin is as effective as etretinate in the combination with bath PUVA.