Long noncoding (lnc)RNAs have recently emerged as key regulators of gene expression. Here, we performed high-depth poly(A)+ RNA sequencing across multiple clonal populations of mouse embryonic stem cells (ESCs) and neural progenitor cells (NPCs) to comprehensively identify differentially regulated lncRNAs. We establish a biologically robust profile of lncRNA expression in these two cell types and further confirm that the majority of these lncRNAs are enriched in the nucleus. Applying weighted gene co-expression network analysis, we define a group of lncRNAs that are tightly associated with the pluripotent state of ESCs. Among these, we show that acute depletion of PAT-14 using antisense oligonucleotides impacts the differentiation- and development-associated gene expression program of ESCs. Furthermore, we demonstrate that Firre, a lncRNA highly enriched in the nucleoplasm and previously reported to mediate chromosomal contacts in ESCs, controls a network of genes related to RNA processing. Together, we provide a comprehensive, up-to-date and high resolution compilation of lncRNA expression in ESCs and NPCs and show that nuclear lncRNAs are tightly integrated into the regulation of ESC gene expression.