Up to now a rare affection difficult to diagnose in its abdominal localizations, actinomycosis is becoming of topical interest because of the appearance of a new form of the disease: utero-ovarian infection associated with an intra-uterine contraceptive device (IUD). A recent case, of surgical expression, is reported and used as a basis for an update of epidemiologic and pathogenic data concerning the affection. Diagnosis should be facilitated by regular cytobacteriologic examinations in women with the IUD, and simple preventive measures should limit the number of severe forms sometimes requiring more or less extensive excision.