The placenta and umbilical cord are crucial to the survival and well-being of the fetus. In fact, disorders of either of these may lead to fetal death or severe morbidity. Yet, they are often not accorded appropriate attention in the prenatal sonographic examination. Similarly, the amniotic fluid often reflects the state of fetal health. Frequently, disorders of the placenta, umbilical cord, and amniotic fluid are picked up during routine ultrasound examination. Without ultrasound, these problems would not be detected and might jeopardize the pregnancy. Detection allows interventions that may improve perinatal and maternal outcomes. However, not infrequently, controversial findings, of uncertain significance, demonstrated on routine sonography lead to anxiety and worry. The goal of this chapter is to address the normal appearances of the placenta, cord, and fluid and to describe several of the more common conditions affecting these structures that the clinician may have to deal within pregnancy.