PIP: The causes of perinatal mortality among 7392 hospital births which occurred in Pelotas, RS, Brazil during 1982, were analyzed using the simplified classification described by Wigglesworth. The main advantage of this classification is that it can be used even in places where postmortems are seldom performed. The perinatal deaths were classified into 5 groups: a) macerated fetuses without malformations; b) congenital malformations; c) immaturity; d) asphyxia, and e) other causes of death. The perinatal mortality rate was 33.7/1000 births, nearly equally divided between fetal and early neonatal deaths, and 8.8% of the babies were of low birthweight. 36% of the perinatal deaths were antepartum stillbirths, and 60% of these weighed 2000 g or more. The 2nd most important cause was immaturity, which accounted for 31% of the deaths. In this latter group, 21% weighed 2000 g or more at birth. These findings, as well as the high birthweight-specific perinatal mortality rates, strongly suggest that there are deficiencies in the antenatal and delivery care in Pelotas that must be corrected promptly. Policies that should be implemented by health planners include: decentralization of antenatal care clinics; utilization in these clinics of the "at-risk" concept to identify women at high risk of delivering low birthweight babies, efforts to increase community participation and home visits in order to attract those pregnant women who do not attend clinics. In addition, it is mandatory that well-trained doctors (obstetricians and pediatricians) should be available 24 hours/day at the maternity hospitals to assist mothers and babies identified as being at high risk. (author's)