Spontaneous subarachnoid hemorrhage due to ruptured berry aneurysm and arteriovenous malformation accounted for 4.4 per cent of all maternal deaths in the State of Minnesota from 1950 to 1973. This catastrophic entiity ranked eighth in frequency regarding all causes of death and third among the nonobstetric causes. An analysis of the 37 deaths among 1,763,824 live births is presented. These 37 patients had delivered 96 infants and had 10 spontaneous abortions prior to current pregnancy. This suggest that pregnancy per se has no appreciable effect upon the occurrence of the hemorrhage. Five of these died in association with labor and delivery, or during a 1 day period-three during labor, one during vaginal delivery, and one only 1 hour postpartum. This is equivalent to 35 per week. On the other hand, 15 occurred during pregnancy (underlivered) (0.4 per week) and 17 during the first 3 months post partum (1.4 per week). These data seem to indicate that labor and delivery increase the risk of spontaneous subarachnoid hemorrhage. The neurologic state of these 37 patients was bad from the very onset of the hemorrhage. Rapid irreversible coma occurred in 34 (76 per cent). Of these 34, 24 (74 per cent) were dead within the first 24 hours and 32 (94 per cent) were dead within the first 4 days following the onset of the hemorrhage.