Marine algae exhibit broad spectrum anti-bacterial and anti-inflammatory activities. Acrosorium polyneurum (A. polyneurum) is a marine red alga and belongs to the family Delesseriaceae. The present research evaluates the antiinflammatory effects of A. polyneurum extract (APE) on pro-inflammatory cytokine production. APE demonstrated substantial inhibitory effects on production of pro-inflammatory cytokine in bone marrow-derived macrophages (BMDMs). APE pre-treatment in the lipopolysaccharide (LPS)-stimulated BMDMs exhibited a robust inhibitory effect on production of interleukin (IL)-12, IL-6 and tumor necrosis factor (TNF)-α. It revealed a robust inhibitory effect on phosphorylation of ERK1/2, JNK1/2 and p38. APE also showed remarkable inhibitory effect on phosphorylation and degradation of IκBα. Furthermore, APE pre-treatment demonstrated substantial inhibition of LPS-induced production of nitric oxide and inducible nitric oxide synthase. Collectively, these data suggest that APE has a noteworthy anti-inflammatory property and deserve further studies concerning its potential use as a medicinal agent for inflammation-related disorders.