Inflammasomes are multiprotein signalling platforms that control the inflammatory response and coordinate antimicrobial host defences. They are assembled by pattern-recognition receptors following the detection of pathogenic microorganisms and danger signals in the cytosol of host cells, and they activate inflammatory caspases to produce cytokines and to induce pyroptotic cell death. The clinical importance of inflammasomes reaches beyond infectious disease, as dysregulated inflammasome activity is associated with numerous hereditary and acquired inflammatory disorders. In this Review, we discuss the recent developments in inflammasome research with a focus on the molecular mechanisms that govern inflammasome assembly, signalling and regulation.