Lycopene, found in tomatoes and tomato products, has antioxidant, anticancer, and anti-inflammatory effects. High-mobility-group box 1 (HMGB1) mediates the pro-inflammatory responses in several inflammatory diseases. In this study, the potential roles of lycopene in the HMGB1-mediated pro-inflammatory gene expressions in the primary human-umbilical-vein endothelial cells (HUVECs) were investigated. The data showed that HMGB1 upregulated the expressions of monocyte chemotactic protein 1 (MCP-1), interleukin-6 (IL-6), secretory phospholipase A2 (sPLA2)-IIA, and prostaglandin E2 (PGE2). Lycopene pre-incubation for 6 h decreased the HMGB1-mediated induction of MCP-1, IL-6, sPLA2-IIA, and PGE2. Further study revealed that the inhibitory effects of lycopene on the HMGB-1 induced expression of pro-inflammatory genes were mediated by the inhibition of two important inflammatory cytokines: tumor necrosis factor (TNF)-α and nuclear factor (NF)-κB. These results suggest that HMGB1 upregulated the expression of pro-inflammatory genes and lycopene inhibited HMGB-1-induced pro-inflammatory genes by inhibiting TNF-α and NF-κB. This finding will serve as an important evidence in the development of a new medicine for the treatment of inflammatory diseases.