Abdomino-pelvic actinomycosis is a condition caused by Actinomyces israelii, a Gram-positive opportunistic bacteria that triggers and develops the infection only in previously injured tissues, and then slowly progresses and spreads until it extrinsically affects the urinary tract. Use of an intrauterine device is a known risk factor to suffer from this disease. Relative risk in IUD users is two- to four-fold higher compared to IUD non-users. Risk increased with prolonged IUD use. Treatment is by removal of the causative agent, surgical resection of necrotic tissues and administration of intravenous Penicillin G, 4 million units every 4 hours for 30 days, followed by Amoxicillin 500 mg every 8 hours for 12 months. This paper contributes two cases of abdomino-pelvic actinomycosis with urinary tract involvement in IUD users. Standard treatment was employed with good evolution.