Persistent partial retention of urine or chronic urinary retention (CUR) is a common problem for which we have little understanding in terms of frequency, natural history, prognosis, or efficacy and comparative effectiveness of treatments. Also unclear are whether and when to suspect, screen, or treat patients for CUR. Standard diagnostic criteria (including the duration and volume of post-void residual [PVR] urine i.e amount of leftover residual urine) have not been established for chronic urinary retention.1, 2 Researchers often define CUR as PVR urine volume greater than 300 ml; however, some studies define it as 100 ml, 400 ml, or 500 ml.1