Actinomycosis is a rare chronic disease caused by Gram-positive, anaerobic bacteria. As a saprophyte it commonly cultured from carious teeth, tonsilar crypts, and gastrointestinal tract. Symptoms may include: multiple abscesses, fever, weight loss. Uncomplicated actinomycosis can be treated medically by high-dose penicylin, or tetracycline. In our report we would
like to reveal a case of 64-year old female after supravaginal hysterectomy because of mycomas two years earlier, who was operated because of a left ovary tumor. Patient was treated with antibiotics because of pyodermatitis several months earlier. Preoperative computed tomography showed findings compatible with left ovary cancer. During the operation the huge tumor of sigmoid was found. The tumor was infiltrating urinary bladder, no changes of ovary were obser-ved. Anterior resection of rectum and regional lymphadenectomy was made. In histopathological examination - actinomycosis.