Proteasome dysfunction can lead to an autoinflammatory disease associated with elevated type I interferon (IFNαβ) and NF-κB signalling, however the innate immune pathway driving this is currently unknown. Here, we identify Protein Kinase R (PKR) as an innate immune sensor for proteotoxic stress. PKR activation was observed in cellular models of decreased proteasome function and in cells from proteasome-associated autoinflammatory disease (PRAAS) patients. Furthermore, genetic deletion or small molecule inhibition of PKR ameliorated inflammation in these contexts. Similarly, proteasome inhibitor induced inflammatory gene transcription was blunted in PKR deficient mice compared to littermate controls. Appropriately, PKR is a rheostat for proteotoxic stress, its activation triggers phosphorylation of eIF2α which prevents the translation of new proteins, thereby promoting a cell’s return to homeostasis. Although traditionally known as a sensor of RNA, under conditions of proteasome dysfunction PKR senses the cytoplasmic accumulation of a known interactor, interleukin 24 (IL-24). Importantly, blocking misfolded IL-24 egress into the cytosol via the endoplasmic reticulum degradation pathway blunted PKR activation and subsequent inflammatory signalling. Cytokines such as IL-24 are normally secreted, therefore cytoplasmic accumulation of IL-24 represents a danger associated molecular pattern for the cell. Thus, we have identified a novel mechanism by which cells sense proteotoxic stress, causing inflammation observed in the disease PRAAS.