Point-of-care ultrasound (POCUS) is a tool frequently used in emergency medicine practice. POCUS is the medical use of ultrasound technology at the bedside for evaluation of acute medical conditions in patient care. POCUS can be a useful adjunct in observation units (OUs) for patients who require longer observation periods than can be accommodated during an acute emergency department (ED) stay. We describe three clinical scenarios in which POCUS could help assess patients in OUs who have a change in clinical condition: focused assessment by sonography in trauma (FAST) POCUS exams, congestive heart failure – cardiac and lung ultrasound, and syncope – cardiac ultrasound.