Predictors of postischemic recovery were determined in adult cats subjected to one hour of global brain ischemia followed by blood recirculation for 3 h or longer. The incidence of postischemic recovery of evoked potentials and of spontaneous EEG activity was determined and related to the following variables: anesthesia (barbiturate or halothane/nitrous oxide), completeness of ischemia, body temperature, plasma glucose, arterial pH, blood gases, blood osmolality, postischemic BP, and cerebral blood flow (CBF). The closest correlation was obtained with the rate of initial postischemic recirculation; CBF above 40 ml/100 g.min resulted almost consistently in EEG recovery. Temperature, arterial pH, plasma glucose, and osmolality also influenced recovery. There was no correlation of EEG recovery with blood gases nor improvement of recovery after incomplete ischemia or barbiturate anesthesia. The results are interpreted in respect to common concepts of ischemic injury and the treatment of postischemic resuscitation disease.