Updated project metadata. Bloom’s syndrome (BLM) protein is a known nuclear helicase that is able to unwind DNA secondary structures such as G-quadruplexes. However, its role in the regulation of cytoplasmic processes that involve RNA G-quadruplexes (rG4s) has not been previously studied. Here, we demonstrate that BLM is recruited to stress granules (SGs), which are cytoplasmic biomolecular condensates composed of RNA-binding proteins and RNAs. BLM is enriched in SGs upon different stress conditions and in an rG4-dependent manner. We show that BLM unwinds rG4s efficiently, thus acting as a negative regulator of SG formation, potentially via its unwinding function. Altogether, our data expand the cellular activity of BLM and shed light on the function that helicases play in the dynamics of biomolecular condensates.