Antioxidant and anti-inflammatory effects of seeds and root extracts (PGSE vs. PGRE) prepared from Platycodon grandiflorum (PG) by ethanol extraction were evaluated. PGSE exhibited greater 2,2-diphenyl-l-picrylhydrazyl (DPPH•) and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS•+) radical scavenging activities and more effectively inhibited production of nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) compare to PGRE. The release of tumor necrosis factor-α (TNFα) was also decreased by 31% at 100 μg/mL of PGSE in LPS-stimulated RAW 264.7 macrophages. LPS-induced elevated expressions of inducible NO synthase, cyclooxygenase-2, and proinflammatory cytokines (interleukin (IL)-1β, IL-4, and IL-6) were significantly downregulated, in a dose-dependent manner, by PGSE treatment. The suppression of nuclear factor κB (NFκB) translocation and stimulation of heme oxygenase-1 induction were related to anti-inflammatory mechanism of PGSE. Based on these findings, PGSE has the potential to be used as a functional agent for the mitigation of inflammation related diseases.