Background:  Preoperative urodynamic testing is recommended by experts, but evidence for clinical benefit is limited.
Aims:  To determine whether urodynamic stress incontinence could be confirmed in women presenting with a history of stress incontinence.
Methods:  History and urodynamic diagnoses of 444 women presenting to a general unit between June 2003 and July 2007 are described.
Results:  Urodynamic Stress Incontinence (USI) or mixed USI and detrusor overactivity were observed in 61% reporting any stress incontinence. 15% who reported no stress incontinence had USI. Compared with a normal urodynamic diagnosis, incontinence occurred more frequently in all other diagnostic categories (P < 0.0001) and was worst in the USI and mixed groups (P < 0.0004). Conclusions:  Urodynamic Stress Incontinence is a more severe entity than stress incontinence diagnosed by history. It is yet to be established if this information benefits patients.