Written and edited by experts in the field, this book brings together the current state of the art in phenotypic and rational, target-based approaches to drug discovery against pathogenic protozoa. The chapters focus particularly on virtual compounds and high throughput screening, natural products, computer-assisted drug design, structure-based drug design, mechanism of action identification, and pathway modelling. Furthermore, state-of the art "omics" technologies are described and currently studied enzymatic drug targets are discussed. Mathematical, systems biology-based approaches are introduced as new methodologies for dissecting complex aspects of pathogen survival mechanisms and for target identification. In addition, recently developed anti-parasitic agents targeting particular pathways, which serve as lead compounds for further drug development, are presented.