Biologic therapies, such as tumor necrosis factor-alpha (TNF-alpha) blockers, are commonly used to treat rheumatological diseases in childhood. Screening patients for tuberculosis (TB) is highly recommended before starting therapy with TNF-alpha blockers. Despite appropriate screening, TB still remains a problem in patients receiving anti-TNF therapy in countries where TB is not endemic. TB in anti-TNF-treated patients is often diagnosed late due to altered presentation, and this delay results in high morbidity and mortality with a high proportion of extrapulmonary and disseminated disease. The aim of this study is to show the course of TB disease in children who are on biologic therapy, in an era where many of the children are BCG-vaccinated and TB is intermediately endemic. We recruited 71 patients with several types of inflammatory diseases. Six of them had a positive test result during TB screening and began taking isoniazid (INH) prophylactically. During the 3 years of follow-up, none of these patients developed TB disease. Biologic agents can be safely used in a BCG-vaccinated pediatric population, as long as patients are closely monitored to ensure that any cases of TB will be detected early.