Heat shock protein 90 (Hsp90) is a highly conserved molecular protein fundamental for homeostasis, found in all living organisms. It is an ATP dependent molecular chaperone with over 200 known client proteins. It is induced by many different stressors, promoting cell survival. It also plays an important role in the maturation and stabilisation of oncogenic and cancer proteins. Thus, Hsp90 inhibitors have been investigated as potential anticancer drugs. Studies have suggested a role for hsp90 in NLRP3 inflammasome-dependent IL-1β secretion. Interleukin-1 beta (IL-1β) is an important pro-inflammatory/pyrogenic cytokine that is essential for host defence against infection, but is also pathogenic in chronic diseases and acute tissue injury. IL-1β is produced as inactive pro-IL-1β. Typically, after ligand binding, inflammasomes are activated, resulting in activation of caspase-1, which cleaves pro-IL-1β into its active form. However, there is recent evidence suggesting that caspase-8 and some other proteases can directly cleave pro-IL-1β in a NLRP3-independent manner. Here, we have uncovered an inflammasome-independent role for hsp90 in IL-1β secretion by macrophages and dendritic cells. Treatment of murine macrophages and dendritic cells with Hsp90 inhibitors (Geldanamycin, 17-AAG, 17-DMAG, onalespib), induces IL-1β release in response to LPS. This is independent of NLRP3, ASC and caspase-1, but dependent on caspase-8 and iNOS. Our data also suggest that this effect is independent of cell death. These data suggest a novel role for hsp90 in repressing IL-1β in LPS-treated macrophages and dendritic cells, which may, in turn, have implications for the use of hsp90 inhibitors.