Objective: To describe clinical, radiological, epidemiological, and microbiological characteristics of pediatric patients with diagnosis of tuberculosis in a period of 15 years.Methods: Retrospective study including children and adolescents younger than 18 years diagnosed with tuberculosis in the Clinical Hospital of the Universidade Estadual de Campinas in São Paulo State, Brazil. Active tuberculosis was defined by the identification of Mycobacterium tuberculosis in culture, microscopy, or histopathological examination. Children with positive clinical history and radiological tests who had been exposed to sick adults or with positive tuberculin skin test were also considered as having active tuberculosis. Statistical analysis compared the data obtained from children younger and older than 10 years of age, since they present a disease pattern more similar to adults.Results: There were 145 identified cases, 61.4% in patients under 10 years of age. The main symptoms reported were coughing (55.9%) and fever (46.9%), and the variables of fever, coughing, weight-loss, and pain were significantly influenced by age, with a higher frequency in older children. Diagnosis was confirmed by culture, microscopy, or histopathology in 67.6% of the cases. The other cases (32.4%) had the diagnosis of tuberculosis based on clinical, radiological, and epidemiological characteristics, as well as tuberculin skin test. The positivity for culture, microscopy, and tuberculin skin test was, respectively, 65.8, 35.7, and 72.3%. History of contact with a sick adult was confirmed in 37.2%, without influence of age.Conclusions: Diagnosis of tuberculosis in children is still a challenge, since all the confirmation tests have low positivity. These results demonstrate the need for new diagnostic methods and improved strategies for searching sick contacts.