The Chernobyl nuclear accident, which occurred on April 26th, 1986, resulted in widespread long-term contamination, mainly due to Cs-137, of large territories where populations live. A project was initiated to assess the Cs-137 body burden and health status, not limited to radiation-induced pathologies, for all children living in a highly contaminated district in Belarus; the aim was to provide detailed information for parents worried about their children's health, without the intention of quantifying the radiation-induced risk. In total, about 2500 children benefited from these check-ups, which included approximately 30 parameters and were repeated three times between 2005 and 2009. The internal Cs-137 burden was rather low; about 50% of children had less than 10 Bq kg(-1). The health indicators reported in this paper are the global health status, physical development, and frequencies of thyroid modifications and cardiac dysfunctions. The Cs-137 body burden or density deposition did not appear to be strongly associated with these health indicators; other parameters, such as quality of living conditions and rural or urban residence, appeared to be more important. The aim of the project was achieved, as the results provided a global overview of the health status and level of internal contamination of children living in a contaminated territory about 20 years after the accident.