Urodynamics (UDS) is the dynamic study of the storage and voiding function of the urinary tract. The goal of the UDS study is to identify the cause of a patient’s voiding symptoms, assess prognosis or the results of prior therapy, or direct management by collecting quantitative measurements while reproducing the patient’s voiding symptoms where appropriate and possible. Several parts of the UDS study are customized for each individual to maximize the utility of the test. This article summarizes the key points to performing a quality UDS study that can evaluate and diagnose disorders of the lower urinary tract.