Extracts of the sponge Hyattella aff. intestinalis showed moderate inhibition against adenovirus. Chromatographic separation of the extracts followed by analysis of spectroscopic data allowed us to elucidate the structures of three new metabolites as 2α-hydroxyspongia-13(16),14-diene-3-one ( 4 ), 3β-hydroxyspongia-13(16),14-diene-2-one ( 7 ), and 2α,3α-diacetoxy-17,19-dihydroxyspongia-13(16),14-diene ( 8 ) and to identify six known ones 1 – 3 , 5 , 6 and 9 . Among the molecules, compounds 1 and 3 showed antiviral activity at IC₅₀ 17.0 and 52.0 µM.