Introduction Actinomycosis is a rare infectious disease caused by Gram-positive bacteria. The most common species is Actinomyces israelii. Among its forms of presentation, the thoracic is the least frequent. Case presentation We report two patients with thoracic actinomycosis, 8 and 13 years old, from different geographical areas of Peru. The first case had empyema necessitans and the second, lung consolidation and recurrent hemoptysis. Both had a certain degree of difficulty i n their diagnosis but responded favorably to antibiotics and surgical treatment. The diagnosis was based on the histopathological study. However, we were not able to ascertain the species of actinomyces. Conclusion Thoracic actinomycosis is rare in children and presents as a parenchymal lesion with possible fistulization to the chest wall. This article is one of the few in the Peruvian literature, constituting a contribution to the knowledge of the disease and its management in pediatrics.