Levels of 18 enzymes and metabolites were measured in liver obtained at autopsy from 41 infants, 28 of whom were found unexpectedly dead at home. Four infants had meningitis, 11 had pathologic findings not clearly sufficient to explain death (SUD), and 13 were considered totally unexplained pathologically (SIDS). The possible contributions of postmortem interval, age and diet to the results are reviewed. No characteristic metabolic profile was recognized amongst SUD and SIDS groups. It is speculated that the amount of glycogen found in liver may provide insight into premortal events and reflect the rapidity of the death mechanism. Five individuals (20%) were suspected of having major metabolic abnormality including glycogenosis (1), urea cycle defect (1), and possibly abnormal levels of carnitine palmityl transferase (3).