The authors propose the use of a novel morphological feature for identification in the diagnosis of ATN in postmortem examinations. This is the tubular epithelial whorl in addition to histological features that differ statistically between ATN and non-ATN control renal tissue samples. The epithelial whorl consists of a coil of epithelium contained within the renal tubule. The presence of tubular epithelial whorls, although not very sensitive, is highly specific (100 percent) to renal tissue that exhibits ischemic ATN in this study. The study also confirmed that tubular epithelium that exhibit proliferating tubular epithelial cells, tubulorrhexis, and interstitial expansion are histological features that help distinguish ATN from autolysis in postmortem samples. This study examined renal tissue from 57 postmortem cases with an antemortem diagnosis of ATN; and 57 age-matched and sex-matched control cases were examined for 10 morphological characteristics. These were epithelial proliferation (Ki-67 immunoperoxidase positivity), fibrin thrombi, tubular epithelial whorls, mitoses, casts, autolysis, tubulorrhexis, epithelial flattening, interstitial inflammation, and interstitial expansion. 1 table 5 figures, and 16 references