Brassica phytochemicals exert a broad spectrum of health-promoting activities. The aim of this study was to investigate the possible beneficial effects of a cauliflower leaf powder (CLP)-enriched diet to prevent inflammation and oxidative stress resulting from injection of lipopolysaccharide (LPS) into rabbits. Animals (24 rabbits) were randomly divided into two groups and fed with a standard diet (SD) or a standard diet supplemented with a 100 g kg⁻¹ diet of CLP. After 60 days, six rabbits of both groups received a LPS injection (100 μg per kg body weight). Serum samples collected after 90 min of LPS injection were assessed for their content of both inflammatory biomarkers such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and matrix-metalloproteinases (MMP-2 and MMP-9) and oxidative stress biomarkers such as thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). LPS increased the levels of TNF-α, IL-6, and TBARS as well as MMP-2 and MMP-9 activities, whereas it decreased the GSH levels and SOD and CAT activities. In conclusion, preventive supplementation with CLP can protect rabbits from the inflammation and oxidative stress induced by LPS.