Introduction and objectives: Salmonella Typhimurium is a facultative intracellular entero-pathogen that remains a risk to public health worldwide. The tools and strategies allowing it to invade and survive in host cells are numerous. Nowadays, it is the only pathogen able to invade host cells using both a trigger and a zipper mechanism, respectively depending on the Type 3 secretion system-1, encoded mainly on Salmonella pathogenicity island I, and of the two invasins Rck (Wiedemann et al. 2016) and PagN (Barilleau et al. 2021). Intracellularly, Salmonella are contained in a Salmonella containing vacuole (SCV) whose maturation leads to an acidic and low divalent-cation environment. Nevertheless, in the last decades several studies gave some evidence for a Salmonella escape from the early SCV, leading to cytosolic hyper replication of the pathogen. As PagN expression was previously shown to dependent on acidic pH and low divalent cation concentration (Lambert and Smith 2008), we explored the potential role of PagN in the SCV. Materials and methods: Gentamicin protection assays to determine adhesion, invasion and multiplication were performed in chinese hamster ovary epithelial cell line. PagN expression was evaluated at several time post-infection by western blot. SCV escaping was considered by two ways to discriminate cytosolic vs vacuolar Salmonella: 1) a gentamicine / chloroquine assay, 2) cytometry and microscopy based on a localization-reporting dual color fluorescent plasmid expressed by Salmonella (Noster et al 2019). Salmonella wild-type, pagN mutant and the complemented strain were used. Lastly, intracellular expression of PagN was imaged through confocal microscopy. Results, discussion and conclusion: PagN is highly expressed by Salmonella Typhimurium in the SCV and a reduced escape of the pagN mutant was observed compared to the wild-type strain leading to a reduced replication of the mutant in the cytosol. The impact of these cytosolic replicative bacteria on reinfection in vivo remains to be evaluated as described recently (Chong et al 2021).