A case is presented of actinomycosis that involved the lung and the liver, which was diagnosed after a computed-tomographic-guided needle biopsy of a liver mass. The diagnosis was made on histological grounds that were based on the staining and morphological characteristics of Actinomyces spp. Imaging techniques suggested a communication between the lung and liver lesions. The regression of the disease was followed during 12 months of therapy. The patient remained free of disease for three months after the cessation of treatment. The relevant literature is reviewed.