Actinomycosis is a quite rare infectious disease caused by bacterias of genus Actinomyces. Due to the nonspecificity and the number of clinical forms actinomycosis intervenes in differential diagnosis of many diseases. Authors describe the actinomycotic process of the right adnexa with secondary affection of the ileocaecal region and the liver, which was simulating by its clinical appearence active Crohn's disease. Conclusive diagnosis had not been established till the surgical revision with histological confirmation was performed. The eventual start of immunosuppressive or biological therapy could have had a markedly negative influence on the course of the infectious disease.

        Key words: actinomycosis, Crohn's disease of the ileocaecal region, intrauterine device (IUD)