Gestational trophoblastic disease (GTD) encompasses a broad spectrum of conditions that includes hydatidiform mole, invasive mole, and choriocarcinoma. Although ultrasound (US) is the examination of choice for initial diagnosis, plain radiography, angiography, computed tomography (CT), and magnetic resonance (MR) imaging all play a role in determining the presence of GTD and the extent of its complications. US shows molar gestations as alternating cystic and solid tissue that fills the entire uterus. CT and MR imaging are useful in detecting myometrial invasion, parametrial extension, and metastasis. Because each imaging technique offers a unique perspective highlighting different aspects of GTD, it is important to understand the pathophysiology and natural history of the disease. Such knowledge in turn leads to a greater understanding of the spectrum of findings seen on various kinds of radiologic images and enables the radiologist to play an important role in directing patient work-up by recognizing the implications of various findings and guiding management decisions.