Autoinflammatory disorders are characterized by innate immune cell-driven inflammatory episodes at disease-prone sites. The inflammasomes, cytosolic sensors of pathogen and host danger molecules, can contribute to a variety of hereditary and wide-spread autoinflammatory diseases via their pathogenic activation of interleukin-1b (IL-1b) and the pyroptotic cell death effector protein Gasdermin D (GSDMD). Although targeted cytokine therapies, in particular anti-IL-1b and anti-TNF, have been efficacious in some of autoinflammatory conditions, they lack efficacy in others, or have not been adequately tested. The development of small molecule inhibitors targeting the epigenetic regulators, Bromodomain and Extraterminal (BET) proteins, has identified BET proteins as key regulators of cell death and inflammation, although their roles in inflammasome signaling remain to be fully explored. In this study we investigated how BET proteins might modulate inflammasome-driven responses. Our findings identify how BET inhibitor targeting of specific bromodomains can potently shut down both inflammasome driven pyroptosis, as well as IL-1b activity. Using a range of gene targeted mice lacking TNF receptor signaling components (e.g. caspase-8, RIPK3 and death ligands) or the inflammasome machinery (e.g. IL-1b, NLRP3, GSDMD, caspase-1 and caspase-11) we delineate a unique inflammasome pathway perturbed by BET inhibitor treatment, and show that this contributes to disease severity in a model of the potentially lethal hyperinflammatory disease, hemophagocytic lymphohistiocytosis (HLH).