We report the clinical and diffusion-weighted MRI (DWI) features of three patients with different types of anoxic brain injury: attempted hanging (hypoxic hypoxia), carbon monoxide poisoning (histotoxic hypoxia), and hanging with cardiac arrest (hypoxic-ischemic encephalopathy, HIE). The first two patients, but not the third, recovered substantial neurological function. The distribution of DWI abnormalities was different and correlated well with the distinct neuropathological features of these entities. The prognosis after anoxic encephalopathy depends on the underlying mechanism and its severity, which may be reflected by DWI abnormalities.