Background: Pancreatic ductal adenocarcinoma (PDAC) is a solid malignancy with adverse outcomes. Our aim was to explore promising critical genes related to the development of PDAC. Methods: Microarray datasets were downloaded, and differentially expressed genes (DEGs) were identified. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted by the Database for Annotation, Visualization and Integrated Discovery (DAVID, version 6.8, national cancer institute, Frederick, MD, USA). A protein-protein interaction (PPI) network of DEGs was built with the Search Tool for the Retrieval of Interacting Genes (STRING) (version 11.0, Global Biodata Coalition and ELIXIR, Zurich, Switzerland, http://string-db.org/), and hub genes were determined using Cytoscape (Version 3.7.2, UC San Francisco & Gladstone Institute, San Diego, CA, USA, http://www.cytoscape.org/). Then, expression of hub genes was confirmed by querying Gene Expression Profiling Interactive Analysis (GEPIA) and Human Protein Atlas (HPA) (version 22.0, the Knut & Alice Wallenberg foundation, Wallenberg, Sweden, https://www.proteinatlas.org/) databases. These results were further confirmed by quantitative real time PCR (qRT-PCR) of PDAC cell lines. The prognostic significance of hub genes was evaluated through Kaplan–Meier plotter, and the diagnostic value was assessed using UCSC (University of California Santa Cruz) Xena. Results: Two downregulated DEGs and 196 upregulated DEGs were identified. These overexpressed genes were primarily enriched in extracellular exosomes, calcium ion binding, cell adhesion, the Phosphatidylinositol 3 kinase (PI3K)/protein kinase B (PKB, also known as AKT) signaling pathway and cancer. 10 highly expressed hub genes, namely Cyclin-Dependent Kinase 1(CDK1), Ribonucleotide Reductase Regulatory Subunit M2 (RRM2), DNA Topoisomerase II Alpha (TOP2A), Abnormal Spindle-Like Microcephaly-Associated Protein (ASPM), Protein Regulator of Cytokinesis 1 (PRC1), ZW10 Interacting Kinetochore Protein (ZWINT), Maternal Embryonic Leucine Zipper Kinas (MELK), Centrosomal Protein 55 (CEP55), Denticleless E3 Ubiquitin Protein Ligase Homolog (DTL), and NIMA Related Kinase 2 (NEK2), were determined, and the increased expression of these screened genes was further confirmed in PDAC cells compared with immortalized human pancreatic ductal epithelial cells (HPDE6). Increased expression of the selected genes had shorter overall survival (OS) and relapse-free survival (RFS) in PDAC. The analyses of receiver operating characteristic (ROC) predicted the area under curve (AUC) of hub genes in PDAC ranged from 0.970 to 0.990. Conclusions: In conclusion, our study suggested that upregulation of CDK1, RRM2, TOP2A, ASPM, PRC1, ZWINT, MELK, CEP55, DTL, and NEK2 is associated with poor OS and RFS, and these genes exhibit high diagnostic value in PDAC. These genes may be potential independent diagnostic markers. Further studies are needed to validate their potential diagnostic and therapeutic values in PDAC.