Pregnancy luteoma (PL) is a rare cause of non-neoplastic masses in pregnancy. PLs are usually asymptomatic. However, general symptoms like pelvic pain, lumbalgia, constipation or virilization due to active hormone secretion can be detected as the clinical findings of these benign cysts. The definitive diagnosis of PL is most commonly possible with a pathological evaluation after surgical intervention. Therefore, we present a successful management of PL with close follow-up until delivery. Beside the suspicion of malignancy by ultrasonography and magnetic resonance imaging (MRI), the cytological evaluation of ascites revealed benign cells which was helpful to decide expectant management.