ABSTRACT: This study aimed to investigate the proteomic landscape of plasma exosomes from patients diagnosed with PDAC and IPMN, compared to healthy controls (CT), in order to identify potential biomarkers with prognostic and diagnostic values. Additionally, the study aimed to understand the functional role of the exosome's proteome in pancreatic neoplasia. We isolated the plasma exosomes and analyzed its proteome by nano electrospray tandem mass spectrometry (nanoLC-MS/MS), and performed downstream statistical and bioinformatics analysis, using the Perseus (v. 6.2.2), MSigDB (v. 2023.1), STRING (v. 11.5), and NCG (v. 7.1) databases. A total of 319 differentially expressed proteins (DEPs) were identified among the exosome samples, but our analyses focused on the 135 proteins that were expressed in at least 70% of each group's samples to ensure their representative proteomes. Comparing PDAC and IPMN exosome proteomes to controls, we identified 24 and 33 differentially expressed proteins, respectively. Some of the most upregulated proteins in PDAC exosomes were CPN1, IGHV2-26, ITIH3, and CLU, while some of the most downregulated were C4BPB, APOB, CFH, and C1QB. In IPMN exosomes, KLKB1, LBP, CFB, and SERPINA1 were the most upregulated proteins while C5, APOD, C3, and C1QA were downregulated. In general, the protein-protein networks and enrichment analyses revealed interesting interaction clusters and pathways related to cancer development, such as the immune system, complement cascade, clotting-related and vesicle-mediated processes, regulation of insulin-like growth factor transport, platelet activation signaling, and G-protein signaling. Our analyses also highlighted candidate cancer drivers, including the upregulated IGLL, LBP, SERPINA1, SERPINA4, SERPING1, and the downregulated APOB, and C3, which were identified in these pathways and may have potential roles in pancreatic tumorigenesis.