The study focuses on the proteomic analysis of the exoproteome and surfaceome of Lactiplantibacillus plantarum CRL681, aiming to explore the molecular mechanisms underlying its antagonistic capacity against enterohemorrhagic Escherichia coli (EHEC). More than 600 proteins were identified by mass spectrometry across both proteomes, of which 285 were characterized as part of the secretome through a detailed analysis with bioinformatics tools and bibliographic references. The analysis of these proteins allowed us to conclude that some of them are involved in functions like energy metabolism, nutrient transport, cell adhesion, genetic information processing, and signaling. Additionally, moonlighting proteins were observed, which possess bacterial adhesion capabilities that may contribute to the L. plantarum CRL681 antagonistic actions against EHEC. This group included ribosomal proteins and peptidoglycan hydrolases, that would be responsible for the EHEC cell lysis observed under in vitro experimental conditions. Furthermore, the co-culture of the CRL681 strain with E. coli revealed differential expression of key proteins, such as the overexpression of glutathione reductase, involved in maintaining redox balance. This proteomic study is a step forward in the understanding of the molecular mechanisms underlying the antagonistic capacity of L. plantarum CRL681 against EHEC.