Topical treatment of psoriasis with calcipotriol has been proven effective. The efficacy of calcipotriol has been compared to that of topical corticoids in a number of studies using subjective visual scoring systems such as the PASI index. The purpose of this study was to compare, with objective data, the efficacy of calcipotriol and clobetasol propionate 0.05% in the treatment of plaque type psoriasis. Transepidermal water loss (TEWL) and laser Doppler velocimetry (LDV) were used to monitor restoration of water barrier and normalization of blood flow, respectively, in psoriatic plaques of the limbs of 24 male patients during 3 weeks of treatment. Data were compared to subjective evaluation using the PASI index of the same areas. Significant differences were recorded during treatment in both groups. The results correlated well with the PASI score. Clobetasol was faster in restoring barrier function than calcipotriol. However, no significant differences were detected between the two groups. The use of vitamin analogues may be effective in the topical treatment of psoriasis by normalizing skin biophysical parameters and minimizing the risks of side-effects induced by potent topical corticoids.