Background. The liver actinomycosis is a rare disease associated with complex differentiation from the liver metastases or hepatocellular carcinoma. Case report. A 50-year old immunocompetent female patient was admitted to the Surgical Department in an exhausted condition, with dyspnea, significant weight loss and intermittent fever in the recent two months. Diagnostic procedures that followed, including abdominal ultrasound and computed tomography led us to the diagnosis of metastatic liver disease of unknown etiology with pleural and pericardial effusion. Intraoperatively, the presence of liver pseudotumor without malignancy in the liver was confirmed. Histological examination confirmed the diagnosis of liver actinomycosis. Prolonged treatment with high dose penicillin was performed and all signs and symptoms resolved completely without further problems. The control abdominal ultrasound finding was normal. Conclusion. Liver actinomycosis has a nonspecific presentation, often mimicking liver tumor. A timely diagnosis as well as a combined surgical and antibiotic therapy is necessary in the treatment of patients with primary disease and prevention of complications.