Failure of upper urinary drainage represents a relatively common urologic emergency. Obstruction of the upper urinary tract can be related to a variety of underlying clinical scenarios. In the current era, technologic advances have facilitated an accurate diagnosis and streamlined treatment. Nonetheless, correct management involves attention to presenting clinical signs and symptoms and an awareness of subtle nuances related to the underlying etiology. In this chapter, we describe the presenting signs and symptoms, differential diagnosis, radiographic testing, laboratory evaluation, acute management, follow-up, and pitfalls associated with failure of upper urinary tract drainage.