WRKY proteins comprise a large family of transcription factors. Despite their dramatic diversification in plants, WRKY genes seem to have originated in early eukaryotes. The cognate DNA-binding site of WRKY factors is well defined, but determining the roles of individual family members in regulating specific transcriptional programs during development or in response to environmental signals remains daunting. This review summarises the recent advances made in starting to unravel the various functions controlled by WRKY proteins.