A retrospective review was conducted of 125 ambulatory monitoring (AM) studies performed on 111 women and 11 men between 1992 and 1996. All patients had had conventional cystometry prior to AM. All tests were interpreted with the aid of event markers and urinary diaries. Ambulatory traces were reported using the definitions derived from Coolsaet's work. To assess the role of AM in routine clinical urological practice, ambulatory diagnoses were compared with those of conventional cystometry. A survey of patient management was carried out by postal questionnaire or review of hospital notes to determine whether AM had influenced patient management. The study showed that 53 of 94 (56.3%) patients with symptoms suggestive of detrusor overactivity had detrusor instability diagnosed on AM. Of those with symptoms suggestive of stress incontinence, 5 (29%) had genuine stress incontinence and 5 (29%) had detrusor instability. The remainder (42%) had normal tests. Overall in 79 of 125 tests (63.2%), additional urodynamic findings were made that correlated with symptoms. Following the survey of patient management, AM was shown to influence management in all but 8.7% patients. In summary, AM was felt to have been shown to be a useful additional tool in clinical urological practice for those patients where conventional cystometry had failed to explain their symptoms.