<jats:title>Abstract</jats:title><jats:p>Six new cerebrosides (ceramide monohexosides), acanthacerebroside A (<jats:bold>1</jats:bold>), B (<jats:bold>2</jats:bold>), C (<jats:bold>3</jats:bold>), D (<jats:bold>4</jats:bold>), E (<jats:bold>5</jats:bold>), and F (<jats:bold>6</jats:bold>) were isolated from the water‐insoluble lipid fraction of the chloroform‐methanol extract of the starfish <jats:italic>Acanthaster planci</jats:italic>. On the basis of chemical and spectral evidences, they were characterized as 1‐<jats:italic>O</jats:italic>‐(β‐<jats:sc>D</jats:sc>‐glucopyranosyl)‐substituted (1<jats:italic>S</jats:italic>,3<jats:italic>S</jats:italic>,4<jats:italic>R</jats:italic>)‐2‐[(2<jats:italic>R</jats:italic>)‐2‐hydroxytetracosanoylamino]‐1,3,4‐hexadecanetriol (<jats:bold>1</jats:bold>), (2<jats:italic>S</jats:italic>,3<jats:italic>S</jats:italic>,4<jats:italic>R</jats:italic>)‐2‐[(2<jats:italic>R</jats:italic>)‐2‐hydroxyhexadecanoylamino]‐1,3,4‐docosanetriol (<jats:bold>2</jats:bold>), (2<jats:italic>S</jats:italic>,3<jats:italic>S</jats:italic>,4<jats:italic>R</jats:italic>,13<jats:italic>E</jats:italic>)‐2‐[(2<jats:italic>R</jats:italic>)‐2‐hydroxyhexadecanoylamino]‐13‐docosene‐1,3,4‐triol (<jats:bold>3</jats:bold>), (2<jats:italic>S</jats:italic>,3<jats:italic>R</jats:italic>,4<jats:italic>E</jats:italic>,10<jats:italic>E</jats:italic>)‐2‐[(2<jats:italic>R</jats:italic>)‐2‐hydroxydocosanoylamino]‐4,10‐octadecadiene‐1,3‐diol (<jats:bold>4</jats:bold>), (2<jats:italic>S</jats:italic>,3<jats:italic>R</jats:italic>,4<jats:italic>E</jats:italic>,10<jats:italic>E</jats:italic>)‐2‐[(2<jats:italic>R</jats:italic>)‐2‐hydroxydocosanoylamino]‐4,10‐octadecadiene‐1,3‐diol (<jats:bold>5</jats:bold>), and (2<jats:italic>S</jats:italic>,3<jats:italic>R</jats:italic>,4<jats:italic>E</jats:italic>,10<jats:italic>E</jats:italic>)‐2‐[(2<jats:italic>R</jats:italic>)‐2‐hydroxytetracosanoylamino]‐4,10‐octadecadiene‐1,3‐diol (<jats:bold>6</jats:bold>). Reversed‐phase HPLC was effective to isolate these cerebrosides revealing the very close resemblance in structure. Negative FABMS spectrometry was useful in providing information on the molecular mass of the cerebrosides.