The importance of protein kinases in cell signaling and cell cycle control has led to detailed structural and functional studies in various eukaryotes, and hence to the synthesis of specific chemical inhibitors for managing disease. Here, the current progress in applying developments from the wider protein kinase field to parasitic protozoa is reviewed. The availability of genome sequence data for several parasites has led to the identification of many protein kinases. Reverse genetics studies, including gene knockout and 'chemical genetics', can help to define the roles of the protein kinases and validate them as drug targets. In addition, screening chemical libraries with active recombinant protein kinases can identify lead compounds for drug design.