To better define the incidence, causes, and risk factors associated with maternal deaths, the Maternal Mortality Collaborative in 1983 initiated national voluntary surveillance of maternal mortality. The Maternal Mortality Collaborative reported 601 maternal deaths from 19 reporting areas for 1980-1985, representing a maternal mortality ratio of 14.1 per 100,000 live births. Overall, 37% more maternal deaths were reported by the Maternal Mortality Collaborative than by the National Center for Health Statistics for these reporting areas. Older women and women of black and other races continued to have higher mortality than younger women and white women. The five most common causes of death for all reported cases were embolism, nonobstetric injuries, hypertensive disease of pregnancy, ectopic pregnancy, and obstetric hemorrhage. Compared with national maternal mortality for 1974-1978, ratios were lower for all causes except for indirect causes, anesthesia, and cerebrovascular accidents. Fatal injuries among pregnant women are not commonly reported to maternal mortality committees. As maternal mortality from direct obstetric causes continues to decline, clinicians will need to emphasize preventing deaths from nonobstetric causes.