Malaria remains one of the most serious global infectious diseases, with an estimated 2 billion people at risk and 1 million deaths annually. Drug resistance is hampering the effectiveness of many current antimalarial therapies and resistant strains of the parasite are now known for almost all classes of antimalarial compounds. Owing to a lack of concerted drug-discovery efforts over the last 30 years, the development pipeline is limited and the identification of new antimalarial lead compounds is a pressing concern. The development of new antimalarials that exhibit novel modes of action is of critical importance if the devastating effects of malaria are to be controlled. Natural products have traditionally played an important role in antimalarial drug development and the marine environment represents an underexplored resource in this regard. This review covers developments in the field of antimalarial drug discovery from marine sources between January 2003 and December 2008 and offers a comprehensive overview of all marine-derived compounds from this period. Marine natural products represent an emerging opportunity in the development of new antimalarial lead compounds. This review provides examples of several recent lead discovery projects that show promise in this regard and presents a perspective on areas of possible future study.