BMSCs can interact with disease processes in a number of organs including the liver. Under most circumstances, current evidence suggests that BMSCs do not play a large role in the repopulation of the hepatic parenchyma, and cell fusion seems to be the predominant process when this does occur. BMSCs may support liver repair, however, through the delivery of growth factors that promote liver regeneration, fibrosis resolution or new blood vessel formation. Conversely, subsets of BMSCs can also contribute to fibrogenesis within the liver in response to injury. The evidence to inform which BMSCs are involved is conflicting, reflecting variances in how individual stem cells are defined and highlighting difficulties in demarcating clear boundaries between the different compartments. An understanding of what regulates BMSC homing to the liver is emerging, and SDF-1/CXCR4 signalling seems central to this. Trials of BMSC treatment in patients with liver disease have already started but are still at a very preliminary stage. A more comprehensive understanding of BMSC physiology in animal models of liver disease is essential to improve the likelihood that such treatment will result in successful clinical treatments in the future.