Marine molluscs and their bioactive compounds are of particular relevance to the growing pool of nutraceutical resources under global investigation. A number of extraction techniques have been developed to isolate bioactive compounds according to their chemical characterization, such as proteins, carbohydrates and lipids. We briefly reviewed those methods in general. Bioactive molecules are 'concealed' in the primary structures of tissue samples of molluscs as amino acids, lipids or carbohydrates which are released by mechanical and chemical processes. The major health benefits of extracts of molluscs include antioxidant, anticancer, and anti-infectious disease activities and cardiovascular protection, which have been reviewed in detail. This review provides a novel view into the efficacy of isolation techniques and subsequent bioactivity analysis of compounds under investigation. Future development in extraction-bioactivity has also been discussed.