This 2-week, randomized, multicenter, investigator-blinded, parallel-group study was conducted to compare the efficacy and safety of augmented betamethasone dipropionate 0.05% lotion and clobetasol propionate 0.05% solution in the treatment of moderate-to-severe scalp psoriasis among 197 (193 assessable) healthy adult patients with at least 20% scalp-surface involvement. The patients received one of two treatments applied twice a day for 2 weeks. Signs and symptoms were evaluated at baseline, after 3 days (day 4), and after weeks 1 (day 8) and 2 (day 15) of treatment. As early as 3 days after treatment, scaling and induration were improved significantly faster by betamethasone dipropionate than by clobetasol propionate. Both treatments also reduced erythema and pruritus. Patients receiving betamethasone dipropionate had a significantly greater mean percent improvement in total sign/symptom scores (P < or = 0.015) at all visits and better mean global clinical response scores at the early visits (days 4 and 8) (P < or = 0.017). At the end of the study, only mild disease was present in both groups. Adverse events were reported by 34.0% and 36.4% of patients receiving betamethasone dipropionate and clobetasol propionate, respectively. All events were transient, most were mild and local, and no discontinuations resulted. The effects of treatment on the hypothalamic-pituitary-adrenal axis were not measured. In conclusion, augmented betamethasone dipropionate lotion and clobetasol propionate solution were equally effective, but betamethasone dipropionate lotion provided a faster onset of relief for scaling and induration, which may enhance patient compliance and patient satisfaction with treatment.