Summary Forty-five patients with extensive chronic plaque or guttate psoriasis were treated with either narrowband (TL-01) phototherapy, etretinate TL-01 combination therapy (re-TL-01) or etretinate and PUVA (re-PUVA) (15 patients in each group). Re-PUVA was the most effective therapy with 100% satisfactory clearance rate. TL-01 monotherapy had an 80% success rate; the relapse rate compared favourably with re-PUVA (50% in remission after 6 months). In the etretinate-TL-01 group, there was a 93% success rate and a one-third reduction in the total irradiation dose (8.0 J/cm2 vs, 12.7 J/cm2) but the relapse rate was higher, only 33% remaining in remission after 6 months.