The NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is a cytoplasmic supramolecular complex that is activated in response to cellular perturbations triggered by infection and sterile injury. Assembly of the NLRP3 inflammasome leads to activation of caspase-1, which induces the maturation and release of interleukin-1β (IL-1β) and IL-18, as well as cleavage of gasdermin D (GSDMD), which promotes a lytic form of cell death. Production of IL-1β via NLRP3 can contribute to the pathogenesis of inflammatory disease, whereas aberrant IL-1β secretion through inherited NLRP3 mutations causes autoinflammatory disorders. In this review, we discuss recent developments in the structure of the NLRP3 inflammasome, and the cellular processes and signaling events controlling its assembly and activation. The NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome, a critical component of the host innate immune system, has an important role in microbial infection, but its aberrant activation causes inherited disorders and contributes to sporadic inflammatory diseases.At steady state, the structure of NLRP3 is oligomeric and kept in an inactive form through interactions among the C-terminal LRR domains. In response to specific stimuli, NLRP3 forms a supramolecular complex, called the inflammasome, which activates caspase-1, leading to the release of interleukin (IL)-1β and IL-18.The NLRP3 inflammasome senses the disturbance of intracellular homeostasis induced by an array of stimuli that converge on K+ efflux, which is critical for NLRP3 activation.Localization of NLRP3 to the dispersed trans-Golgi network has been suggested to have an important role in NLRP3 activation.Post-translational modifications regulate the NLRP3 inflammasome at both the priming and activation steps.