Uterine rupture is a rare and life-threatening condition. It usually occurs in patients with uterine scars (most commonly for a previous myomectomy or caesarean section), but it can also affect an unharmed uterus. This complication is more frequent in the third trimester and during delivery. There is not yet a recognised method of prediction of uterine rupture and the ultrasound features still need a consensus. In this article, we have reported a case of uterine dehiscence diagnosed by a pelvic ultrasound and magnetic resonance (MRI) at 24 weeks of gestation. The finding was confirmed intraoperatively at the caesarean section at 29 weeks of gestation. The 40-year-old patient has had a previous pregnancy complicated by uterine rupture at 22 weeks of gestation, following six previous abdominal surgeries for stage IV endometriosis, diffuse and nodular adenomyosis, and pelvic adhesion syndrome. The early detection of uterine dehiscence allowed us to prolong the pregnancy and perform a subsequent fertility-sparing surgery, reducing maternal and neonatal morbidity and mortality. Our case report proves that women with severe endometriosis/adenomyosis are at a high risk of uterine rupture and scar dehiscence. The antenatal ultrasound can describe a uterine dehiscence (even in asymptomatic patients) and prevent complications.