Psoriasis is a chronic inflammatory disease. Within psoriatic lesions, microvascular dysfunction and numerous, tortuous blood vessels occurs. The Nd:YAG laser causes the selective destruction of dilated capillaries, which contributes to the inhibition of leukocyte transport within psoriatic lesions and may be an effective method of psoriasis therapy. This preliminary study was designed to assess the effectiveness of the Nd:YAG laser in reducing psoriatic lesions. Twenty volunteers suffering from psoriasis met the inclusion criteria and were qualified for the study. The non-lesional skin areas and areas with psoriatic lesions were imaged using a DUB SkinScanner high-frequency ultrasound, and skin parameters, including the stratum corneum hydration, melanin and hemoglobin level, were evaluated. The thickness of the epidermis and the SLEB layer, as well as the density of the dermis, were assessed before and after the therapy. The Nd:YAG laser, with a wavelength of 1064 nm and a 650-microsecond pulse duration, was used to treat psoriasis. The density of psoriatic skin after treatment increased by 7.26 u.m. and epidermis thickness decreased by 0.068 u.m. The stratum corneum hydration increased by 9.5 u.m., hemoglobin value decreased by 35 u.m. and melanin decreased by 12 u.m. The thickness of the SLEB layer was also reduced from 0.340 mm before the therapy to 0.195 mm after the therapy. The increase in skin density and the decrease in epidermal thickness after the therapy may prove the effectiveness of the Nd:YAG laser in reducing psoriatic lesions. The thickness of the SLEB layer and hemoglobin decrease indicate a reduction in inflammation. Laser therapy improves the epidermal hydration of psoriatic skin.