Work during the past several years has produced new insights into many aspects of the cell biology of ischemic injury to the tubulointerstitium. The major processes are conveniently considered in terms of early events, the prelethal and lethal cell injuries that occur during the period of ischemia and in the first hours of reperfusion, and late events, the proliferation and fibrosis which repair and restructure the damaged tissue. Most currently available data are pertinent to understanding the early events at the tubule cell level, and this information will necessarily comprise most of the review.