Sulforaphane [1-isothiocyanato-4-(methylsulfinyl)-butane] is one of the most abundant isothiocyanates in some cruciferous vegetables, especially broccoli. Sulforaphaene has been shown to exhibit many pharmacological activities, including anti-oxidant, anti-inflammatory and anti-microbial activities. However, the anti-skin photoaging effects of sulforaphane have not yet been reported. In the present study, we investigated the inhibitory effects of sulforaphane on MMP-1 and -3 expressions of the human dermal fibroblasts via various in vitro experiments and elucidated the pathways of inhibition. Western blot analysis and real-time PCR revealed sulfiraphane inhibited UVB-induced MMP-1 and -3 expressions in a dose-dependent manner. UVB strongly activated nuclear factor-κB (NF-κB) activity, which was determined by NF-κB DNA binding activity. UVB-induced NF-κB activation and MMP expression were completely blocked by sulforphane. These findings suggest that sulforaphane could prevent UVB-induced MMPs expressions through inhibition of NF-κB activation.