OBJECTIVE: The description of rare case of the Cushings syndrome in pregnancy resulting in the spontaneous rupture of uterus. DESIGNS: A case report. SETTING: Department of Gynecology and Obstetrics, 1st Medical Faculty of Charles University and Hospital Na Bulovce. CASE REPORT: The authors report the case of a 33 year old woman, who was admitted to the clinic in 30th week of pregnancy for elevated blood pressure and hypokalemia. Arterial hypertension was corrected with the combination of Vasocardin and Dopegyt. In 36th week of pregnancy the patient was admitted to the hospital with premature rupture of membranes. In less than sixteen hours the patient spontaneously gave birth to a healthy girl. Subsequently the patient suffered from abdominal pain. CT scan showed haemoperitoneum and a right adrenal mass and the surgical revision was performed. During the surgery uterine rupture was identified and the patient uderwent abdominal hysterectomy. Based on the endocrinological examination the diagnosis of Cushings syndrome was made. Three months after the delivery she underwent laparoscopic right adrenalectomy. Histological examination revealed adrenocortical oncocytoma. CONCLUSION: Cushings syndrome is rare in pregnancy and misdiagnosis is common. Symptoms mimic pregnancy complications. The disease is often diagnosed with delay even after delivery. The sonography and magnetic resonance are dominant imaging methods. Laboratory diagnosis is difficult due to pregnancy related changes. In spite of rarity of Cushings syndrome in pregnancy we should think about it in terms of the differential diagnosis of hypertension, diabetes, dysbalance of mineralogram and typical cushingoid habitus.