Background - Following the 2004 publication of the decree abolishing routine tuberculin testing in children, the City of Paris considered the appropriateness and optimal methods for continuing tuberculosis screening in schools. Method - A study was conducted in Parisian schools among fifth-grade students. It consisted of a case-control study exploring individual risk factors for an abnormal tuberculin intradermal reaction (IDR), followed by an analysis of 2004 testing data to compare the impact and efficiency of five different strategies for identifying children to be included in tuberculosis screening. Impact was measured by the number of tuberculosis infections detected and treated, and efficiency by the average number of tests required to detect a tuberculosis infection that was treated. Results - Aside from a history of multiple BCG vaccinations, the main risk factor for a child to have an abnormal IDR result is the fact that at least one of their parents was born in a country with high tuberculosis prevalence. Of the five testing strategies considered, two can be selected based on their effectiveness and efficiency: the strategy of testing all children and the strategy of testing only children with individual characteristics that place them at high risk for tuberculosis. Discussion - The decision in Paris, as in other major French cities, regarding the strategy to adopt will depend on the local epidemiology of tuberculosis and the resources available for school-based screening, and must take into account the regional specificities of the new BCG vaccination policy. (R.A.)