Abstract: Korean Red Ginseng (KRG) is a representative traditional herbal medicine with many different pharmacological properties including anti-cancer, anti-atherosclerosis, anti-diabetic, and anti-inflammatory activities. Since only a few studies have explored the molecular mechanism of KRG-mediated anti-inflammatory activities, in this study we aimed to investigate the anti-inflammatory mechanisms of the protopanaxadiol saponin fraction (PPD-SF) of KRG using in vitro and in vivo inflammatory models. PPD-SF dose-dependently diminished the release of inflammatory mediators [nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin E2 (PGE2)], and downregulated the mRNA expression of their corresponding genes [inducible NO synthase (iNOS), TNF-α, and cyclooxygenase (COX)-2], without altering cell viability. The PPD-SF-mediated suppression of these events appeared to be regulated by a blockade of p38, c-Jun N-terminal kinase (JNK), and TANK-binding kinase 1 (TBK1), which are linked to the activation of activating transcription factor 2 (ATF2) and interferon regulatory transcription factor 3 (IRF3). Moreover, this fraction also ameliorated EtOH/HCl-induced gastritis via suppression of phospho-JNK2 levels. Therefore, these results strongly suggest that the anti-inflammatory action of PPD-SF could be mediated by a reduction in the activation of p38-, JNK2-, and TBK1-linked pathways and their corresponding transcription factors (ATF2/IRF3).