OBJECTIVE: This paper aimed to test the reliability of two questionnaires in studies involving children and adolescents (aged 3-18 years) in seven South American cities. One assesses socioeconomic status (SES) and the other measures environmental factors. METHODS: The SES questionnaire was composed of 14 questions, which included the presence of several consumer goods, domestic services, family income, parental education level, and current parental occupation status. The environmental questionnaire was composed of 15 questions to measure the social and infrastructure characteristics of the area of residence. Parents or guardians completed the questionnaires on behalf of their children. Adolescents answered the questions themselves for environmental factors, while those related to SES factors were answered by their parents or guardians. We analyzed the reliability of the questionnaires through kappa coefficient determination. Multilevel linear regression models were applied to calculate the correlation between the total household scores, the household income, and parents' education level. RESULTS: The environmental questionnaire showed good reproducibility in both age groups (k = 0.132-0.612 in children and k = 0.392-0.746 in adolescents). The SES questionnaire showed strong reliability in both age groups for all indicators (k = 0.52-1.00 in children and k = 0.296-0.964 in adolescents). CONCLUSIONS: Our multiple indicator questionnaires focused on environmental factors and SES in pediatric health surveys provided useful and easily applicable additional indicators to measure these important determinants of cardiovascular health.