The aim of this paper is to evaluate the role of apoptosis in some common liver diseases, and the utility of M30, an apoptotic serum marker, in the diagnosis of the severity of underlying hepatic injury. As is widely known, apoptosis is programmed cell death, and its deregulation results in an uncontrolled inflammatory process leading to upregulation of liver fibrogenesis. Both extrinsic and intrinsic pathways are crucial in apoptosis, and caspase cleavage of cytokeratin proteins occurs in both. Therefore, the measurement of caspase-cleaved cytokeratin fragments could be a novel method to assess the intensity of apoptotic cell numbers in epithelial tissue damage. M30 levels were found to increase not only in acute liver disorders, but also in some chronic liver injuries. We tried to summarize the recent studies focused on the role of apoptotic processes in liver diseases, mainly those that investigated the use of M30 in determining the severity of, or in predicting, ongoing liver injury.