Ultrasonography is a safe, relatively inexpensive, and portable imaging modality. With the increasing availability of mobile, portable, and pocket-sized ultrasound machines, point-of-care transthoracic echocardiography has become a bedside tool to serve in medical emergencies and in peri-operative settings to assess the hemodynamically unstable obstetric patient in a timely fashion. In managing obstetric critical illness, some characteristics of pregnant women facilitate a focused cardiac examination, including anterior and left lateral displacement of the heart, spontaneous ventilation, and familiarity with ultrasound use. It supplements the physical examination, basic investigations, and aids in the diagnosis of significant cardiac pathology. While many acronyms exist, such as bedside echocardiography, point-of-care echocardiography, hand-held echocardiography, or goal-directed echocardiography, national and international scientific bodies have agreed on the terminology “focused cardiac ultrasound” or FoCUS. This chapter provides an overview of the definition, techniques, and diagnostic aims of a FoCUS examination and its clinical applications in obstetric cardiac disease. The chapter concludes by summarizing certification standards and training requirements.