Kupffer cells, the resident macrophages of the liver, not only exert phagocytosis but also excrete proinflammatoiy cytokines. Large amounts of cytokines, produced by activated Kupffer cells, can induce aggravate liver ischemia/reperfusion (I/R) injury. Also, Kupffer cells that express protective genes protect from I/R injury after liver transplantation. Due to their key location, Kupffer cells might function as antigen-presenting cells and participate in transplantation immunity. They also seem to play a key role in innate immune responses and host defence through the expression and secretion of soluble inflammatory mediators. With this review we want to assist in improving the understanding of the contribution of Kupffer cells in liver I/R injury and the development of the transplantation immune. We hope that the delineation of the complex mechanisms of dysregulation may inspire the design and development of novel treatment approaches.