The RNA exosome is a multi-subunit protein complex involved in RNA surveillance of all classes of RNA, and essential for pre-ribosomal RNA processing. The exosome is conserved throughout evolution, present in archaea and eukaryotes from yeast to humans, where it localizes to the nucleus and cytoplasm. Despite being considered as a protein present in these two subcellular compartments, here we show that the yeast exosome catalytically active subunit Rrp44/Dis3 not only localizes mainly to the nucleus, but is concentrated in the nucleolus, where the early pre-rRNA processing reactions take place. Moreover, we show by confocal analysis that core exosome subunits Rrp41 and Rrp43 also localize largely to the nucleus and are concentrated in the nucleolus. The results shown here shed more light on the localization of the yeast exosome and have implications regarding the main function of this RNase complex, which seems to be primarily related to early pre-rRNA processing and surveillance.