An ecological study was carried out with the aim of analyzing the evolution of inequalities in mortality in Salvador, Bahia State, Brazil, between 1991 and 2006. The city was divided into four social strata from 95 geographic Information Zones. The variables used for social stratification were education level and income of heads of households. Crude and age-standardized mortality rates, age specific mortality rates, proportional Infant mortality and the proportional mortality ratio, were calculated for each zone and social strata. Data was obtained from Death Certificates and the Populational Census. Although differences between strata were smaller in 2000 than in 1991, they persist and are still high, ranging from 28.7% to 65.5%. The differences between Information Zones were as much as 575%. The authors discuss the shortcomings of information systems, recommending that health indicators should be estimated by social classes and pointing out the limits and possibilities of the methodology used here.
