Matrix metalloproteinase 13 (MMP13) is a zinc-containing endopeptidase secreted by keratinocytes and skin fibroblasts and participates in many inflammatory diseases. Drugs for retinoic acid include tazarotene and acitretin. Tazarotene/acitretin and narrow-band ultraviolet B (NB-UVB) irradiation are used as a general treatment for psoriasis. However, their impact on MMP13 expression has yet to be determined. In this study, we measured the expression of MMP13 in patients with psoriasis, and investigated the effects of tazarotene and/or NB-UVB on MMP13 expression in a mouse model of psoriasis. After exposure to acitretin and/or NB-UVB, immortalized human HaCaT keratinocytes were analyzed for viability and MMP13 expression. Our results showed that MMP13 protein levels increased in skin lesions and serum samples in patients with psoriasis. Treatment with acitretin and NB-UVB irradiation alone or in combination suppressed cell viability and MMP13 expression in HaCaT cells. Consistently, tazarotene treatment and/or NB-UVB irradiation attenuated imiquimod-induced psoriasis-like dermatitis and inhibited MMP13 expression in a mouse model. Taken together, these results indicate that tazarotene/acitretin and NB-UVB irradiation can inhibit the expression of MMP13 in keratinocytes and psoriasis mouse models. Targeting MMP13 may represent a promising therapeutic strategy against psoriasis.