Due to the findings in 10 children with tuberculosis, which has been proved by cultural methods or animal test, it is advisable to take the following into consideration: The possibility of tuberculosis must be assumed for each BCG-vaccination child, that shows symptoms of disease of uncertain aetiology and that has had or might have had contact with a person with active tuberculosis. Among the diagnostic procedure proof and typing of the tubercle bacillus are considered to be most important.