Low-cost alternatives that allow for the monitoring of population groups are important strategies in conducting cohort studies. This paper presents the procedures for the use of the National School Census as a search tool for children and adolescents in follow-up studies. The study was conducted among adolescent students who took vaccinations in clinics in Cuiabá, Mato Grosso State, Brazil in 1999. A total of 86.8% were identified in the census and 0.2% in the Mortality Information System. Of those identified, 1,716 were interviewed, representing a follow-up rate of 71.4%. In this study, the school census proved to be an effective method for finding students.