Tubo-ovarian abscess in the third trimester of pregnancy is extremely rare. In this report, an unusual case with asymptomatic tubo-ovarian abscess, diagnosed incidentally during Cesarean section performed for an obstetric indication, is presented. Unlike other reported cases, no signs or symptoms attributable to pelvic abscess throughout the pregnancy were observed in our patient. To our knowledge, this is the first report of such a case in the literature.