Between 1981-84 the 1st survey (EMIS) took place in 2 rural communities in Senegal: Fissel and Thienaba in the Thies Region. The survey aimed to measure levels of infant mortality (IMR) for those under 2 and to study the determinants of mortality. The survey was done in 2 phases: 1) follow-up of all live births for 1 year in the selected sites, and 2) 8 follow-up stages of infants for 28 months. Since the majority of women delivered at home, the following strategies were instituted to register all newborns: 1) registration of all pregnant women in the survey; 2) assignment of permanent observers in all villages to register all births and deaths. Certificates were developed for these purposes; and 3) re-designing the survey zones into sub-zones. To verify that the survey had not omitted anyone, checks were made on civil registrations and a census was taken followed by individual questionnaires issued to all women in reproductive ages. Results were IMR of 113/1000 for ages 0-1; 180/1000 for those ages 0-2. In 1986 the IMR was estimated at 91/1000 for the country and 102/1000 for the rural areas. For Thienaba the IMR was 99/1000 and 149/1000 for those under 2. Fissel the IMR was 127/1000 and 199/1000 for those under 2. The discrepancies are due to the lack of trained personnel. Out of a total of 3056 women, 62% had made a prenatal visit; however, 72% of women in Thienaba as against 48% in Fissel had 1 prenatal visit. 16% of women delivered in health centers. In Thienaba there was greater coverage for vaccination (44% for tuberculosis and 34% against measles) than in Fissel (35% for tuberculosis and 19% against measles). Infectious and parasitic diseases were the most common reasons for infant mortality; 29% was caused by malaria and 18% by diarrhea.