Purpose. To assess the clinical value of sonography for the follow-up of mediastinal lymph-adenopathy in children diagnosed with pulmonary tuberculosis (TB). Methods. We conducted a retrospective review of the medical records of 21 children (9 boys, 12 girls) with a mean age of 6 years (range, 7.4 months to 18 years) who had a positive intradermal tuberculin skin test. All patients underwent thorough history-taking, physical examination, frontal and lateral chest radiographs, and sonographic study of the mediastinum. The mediastinum was accessed through the suprasternal and left parasternal approaches. The presence of 1 or more masses with an ovoid or round shape and hypoechoic appearance in the anterior or middle mediastinum was recorded. A comparison was made between the results of the sonographic examination of the mediastinum before administration of anti-TB agents and after 3 months of treatment. Results. Pulmonary radiographic findings were suggestive of TB in 17 patients and were uncertain in 4 patients. Sonographic examination, however, detected mediastinal lymphadenopathy in all patients. A comparison of pretreatment mediastinal sonograms with those obtained after 3 months of anti-TB treatment showed a marked reduction of lymph node involvement in 17 patients (80.9%). In the remaining 4 patients, mediastinal lymphadenopathy was still present. Conclusion. Mediastinal sonography appears to be a valuable tool for the diagnosis of TB and in the monitoring of response to treatment in children. © 2007 Wiley Periodicals, Inc.