We have previously demonstrated that the Bcl-2/adenovirus EIB 19kD-interacting protein 3 (BNIP3), a cell death-related member of the Bcl-2 family, is upregulated in vitro and in vivo in both experimental and clinical settings of redox stress, and that nitric oxide (NO) downregulates its expression. Here, we sought to examine the expression and localization of BNIP3 in murine hepatocytes and in a murine model of hemorrhagic shock (HS) and ischemia/reperfusion (I/R). Freshly isolated mouse hepatocytes were exposed to 1% hypoxia for 6 hr followed by reoxygenation for 18 hr, and protein was isolated for Western blot analysis. Hepatocytes grown on coverslips were fixed for localization studies. Similarly, livers from surgically cannulated C57Bl/6 mice and mice cannulated and subjected to 1-4 hr hemorrhagic shock were processed for protein isolation and Western blot analysis. In hepatocytes, BNIP3 was expressed constitutively but was upregulated under hypoxic conditions, and this upregulation was countered by treatment with a NO donor. Surprisingly, BNIP3 was localized in the nucleus of normoxic hepatocytes, in the cytoplasm following hypoxia, and again in the nucleus following reoxygenation. Upregulation of BNIP3 partially required p38 MAPK activation. BNIP3 contributed to hypoxic injury in hepatocytes, since this injury was diminished by knockdown of BNIP3 mRNA. Hepatic BNIP3 was also upregulated in two different models of liver stress in vivo, suggesting that a multitude of inflammatory stresses can lead to the modulation of BNIP3. In turn, the upregulation of BNIP3 appears to be one mechanism of hepatocyte cell death and liver damage in these settings.