Background: Liver cells represent an attractive source of cells for autologous regenerative medicine. The present study assesses the liver cells’ stability during in vitro expansion, as a prerequisite for therapeutic use. Results: The human liver cell cultures in this study were propagated efficiently in vitro for at least 12 passages. No significant changes in morphology, intracellular ultrastructures and characteristic markers expression were found during in vitro expansion of cells from all analyzed donors. However, expanded cells derived from male donors of >60 years old, lost the Y chromosome. Conclusion: Liver-derived cell cultures adopt a proliferative, stable mesenchymal phenotype, through an epithelial to mesenchymal transition process. The molecular and phenotypic changes of the cells during propagation are uniform, despite the heterogeneity of the different donors. Loss of Y chromosome occurs after cells’ propagation in elder male donors.