Marine algae are rich sources of various biologically active compounds with potential pharmaceutical properties. In the present study, we investigated the inhibitory effects of Plocamium telfairiae extract (PTE) on proinflammatory cytokine production in bone marrow-derived macrophage (BMDMs) and dendritic cells (BMDCs). PTE pre-treatment in LPS-stimulated BMDMs and BMDCs showed a strong inhibition on interleukin (IL)-12 p40, IL-6, and tumor necrosis factor (TNF)-alpha production as compared to non-treated controls. PTE pre-treatment showed significant inhibition on phosphorylation of mitogen-activated protein kinases and degradation of inhibitor of kappa B (IkappaBalpha). Taken together, these results suggest that PTE may have potential anti-inflammatory property and hence, warrant further studies concerning the potentials of PTE for medicinal purpose.