Haemozoin (malaria pigment) is a haem polymer resulting from the breakdown of haemoglobin by Plasmodium spp. This refractory substance has been the focus of many studies and of much debate, mainly because of its role in the pharmacological activity of certain antimalarials. Haemozoin is also important because its presence in tissues serves as an indicator of malaria infections, and may itself be a mediator of malaria pathogenesis. In this article, Amy Sullivan and Steven Meshnick review the structure and synthesis of haemozoin, and then focus on methods of haemozoin identification in tissue. This latter aspect has implications for the study of haemozoin both as an indicator of malaria infection and as a possible mediator of malaria pathogenesis.