Bladder and urethral pressure responses to increasing intraabdominal pressure were studied in anesthetized cats. The results indicate that urethral responses are entirely passive and dependent on the intraabdominal position of the urethra. Urethral resistence to urine flow was not influenced by curare administration or complete sacral rhizotomy but was markedly decreased by phentolamine administration or the application of pressure directly to the bladder.