A review of articles concerning ambulatory urodynamic monitoring (AUM) is given AUM, as we practice it, is described. Typical findings in normal continent women, in patients with genuine stress incontinence, unstable detrusor, mixed incontinence, low closure pressure, unstable urethra and during sitting, jumping, and running are given. AUM is indicated and is superior to conventional cystometry in urge incontinent patients and in patients with a supine closure pressure lower than 20 cm H2O. AUM is also indicated in stress incontinent patients not leaking during stress test. AUM may be valuable in drug effect studies and in the study of normal physiology. Abnormalities which are not disclosed with conventional techniques may better be detected by AUM when patients are at their case alone, free from medical observers or are physically or mentally stressed in the situation they usually leak. AUM may, because of the recording of both urethral and bladder pressures, contribute to a more complete understanding of the leak mechanisms.