The article represents a clinical observation of the development of disseminated TB in a 12-year-old child with HIV infection, a high CD4 lymphocyte count (1315 cells/μl), and undetectable viral load (<20 copies per ml of blood). Perinatal transmission occurred, HIV infection was diagnosed immediately after birth, ART was administered from the first days of life. The girl has lived in a foster family since the age of 12 months. Poor adherence to treatment resulted in raised viral load. At the same time, the girl got ill with severe measles. ART was corrected with a rapid positive immunological and virological effect. One year later, TB manifested under the guise of acute bronchopulmonary disease. The examination revealed traces of infancy intrathoracic lymph node TB in the form of small calcinates. The patient had not been previously examined for TB infection and never received preventive TB treatment. The development of acute progressive TB in the child with HIV infection and satisfactory immunological and virological indicators was caused by: lack of due interdisciplinary (pediatricians, infectiologists, phthisiologists) and interdepartmental (medical services, children’s services) interactions; poor adherence to treatment; past measles.