Fish bones are the by-products of aquatic and fishery processing, which are often discarded. However, it has been considered having health-promoting by containing many essential nutrients. This study investigates the anti-inflammatory effect of fish bone fermented by Monascus purpureus (FBF) and the NF-κB pathway regulation mechanism in lipopolysaccharides (LPS)-induced RAW 264.7 cells. FBF has inhibited the production of PGE2 (prostaglandin E2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in LPS-induced RAW264.7 cells. The FBF has significantly inhibited mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, FBF has suppressed activation of NF-κB (nuclear factor kappa-B) by increasing IκB mRNA expression and reduced of p65, p50 mRNA expression, as well as nuclear NF-κB DNA binding activity in LPS-induced RAW 246.7 cells. These findings demonstrate that FBF has inhibited LPS-induced inflammation by subsiding the activation of NF-κB in RAW 246.7 cells, implying that FBF could be employed as a promising natural product.