Abstract Objective: To describe the chest computed tomography (CT) findings in immunocompetent children under 36 months of age with pulmonary tuberculosis. Materials and Methods: This was a descriptive case series conducted in the city of Rio de Janeiro, Brazil, between January 2004 and July 2013, involving 20 young children who underwent CT after undergoing chest X-rays that did not provide a definitive diagnosis. Results: All of the participants had lymph node enlargement and consolidations. In 15 cases (75%), the consolidations were accompanied by atelectasis. Pulmonary cavitation was seen in 10 cases (50%), and cavitation within consolidations was seen in 7 (35%). The areas of cavitation and parenchymal destruction were not seen on conventional chest X-rays. Conclusion: The radiological presentation of pulmonary tuberculosis in young children differs from that described in older children and adults. CT is an effective method for the early diagnosis of pulmonary tuberculosis in immunocompetent infants, allowing the rapid institution of specific treatment, which is crucial for halting disease progression, as well as for preventing local and systemic complications.