Natural product researchers, armed with a suite of 2D NMR methods and knowledge of biosynthetic pathways, can usually deduce the planar structure of a complex natural product without difficulty. The more complex task of assigning stereochemistry (that is relative and absolute configuration) presents more of a challenge. In this talk, I will describe some of the marine natural products chemistry undertaken in our research group with an emphasis on how stereochemical issues have been resolved using long range coupling constant information. Examples include 3-alkylpiperidine alkaloids from the Balinese sponge Halichondria,1 the diterpene thuridillins from the sacoglossan Thuridilla splendens2 as well as the fungal metabolite acremine Q from a marine-derived fungus3 . HSQC-HECADE or EXSIDE data, together with conformational analysis, NOESY experiments and 1H-1H coupling studies enabled assignment of individual relative configurations.