Updated project metadata. The MYCN oncoprotein forms a DNA-binding heterodimer with its partner protein MAX. MYCN-driven tumor cells depend on the nuclear exosome, a 3`-5` RNA exonuclease complex, to progress through S phase. Here we show that MYCN forms stable high molecular weight complexes with the nuclear exosome and additional RNA-binding proteins. Enhanced cross-linking and immunoprecipitation (eCLIP) experiments reveal that MYCN binds to thousands of sites on RNA, mainly localized in introns. MYCN directly binds RNA with a preference for UG-rich sequences via a short, highly conserved sequence motif termed MycBox I. Upon exosome inhibition, MYCN relocalizes globally from promoters to intronic RNAs; at promoters, MYCN is then replaced by the repressive MXD6 (MNT) protein, leading to the recruitment of histone deacetylase complexes and inhibition of MYCN-dependent transcription. MYCN is tightly associated with the exosome targeting complex NEXT and promotes the degradation of non-polyadenylated RNA at its bound introns. Our data demonstrate that MYCN is an RNA-binding protein that controls nascent RNA turnover and argue that the competition between RNA- and DNA-bound states of MYCN links the dynamics of the MYCN/MAX/MXD network to the completion of mRNA processing.