Five new <i>ent</i>-pimarane diterpenoids <i>ent-</i>16-nor-2-oxopimar-8(14)-ene-15,19-dial (<b>1</b>), <i>ent-</i>16-nor-2α,19-dihydroxypimar-8-en-15-al (<b>2</b>), 3-<i>O</i>-acetyldarutigenol (<b>3</b>), 19-<i>O-</i>acetylkirenol (<b>4</b>), <i>ent</i>-16-nor-3<i>β</i>,15-dihydroxypimar-8(14)-ene (<b>5</b>) were isolated and characterized from the ethanol extract of <i>Sigesbeckia pubescens</i>. Their structures were elucidated on the basis of spectroscopic analysis. The absolute configuration of C-15 in compounds <b>3</b> and <b>4</b> was assigned using Snatzke's method. All these compounds were assessed for their anti-inflammatory potential by measuring the inhibitory effects on NO production in LPS-induced RAW 264.7 macrophage cells and compound <b>4</b> showed significantly inhibitory activity with IC₅₀ value of 5.9 μM.