This review represents a highly personal view of only some of the advances made on the biology of malaria in the period 1986-1987. Progress has stemmed largely from new or refined techniques applied to the logical demonstration of eukaryotic principles; and more rarely from either new conceptual advances, or the revelation of critical differences in the biology of Plasmodium from that of other eukaryotes. Significant steps have been made in the recognition of the complexity of interaction between the parasite and both its vertebrate and invertebrate hosts. It is this very complexity of interaction which warns against the presumption that the successful application of any single control strategy is imminent.