Five asmarines, the known A and F and three new ones, I, J, and K, and four diterpenes, the known chelodane, barekoxide, and zaatirin and a new one, nosyberkol, were isolated from the Nosy Be Islands (Madagascar) sponge Raspailia sp. The structures of all these compounds were established on the basis of MS and NMR data. A biogenesis for the various Raspailia sp. diterpenes is suggested.