Membrane deformations, generally termed blebs, are a hallmark of cells subjected to noxious stimuli or injurious conditions. Although not lethal itself, bleb formation has been used as an indicator of the stage of cell injury. Whether or not bleb formation is an integral part of the sequence of events that lead to irreversible injury, or occurs in all cells within a group subjected to the same conditions is not known. We demonstrate here that renal epithelial cells in culture produce blebs when subjected to sustained periods of anoxia and substrate deprivation. However, the occurrence of blebs does not correlate with eventual cell death. The data suggest that bleb formation may be associated with prolonged survival.