To ascertain the mode of action and benefits of transcutaneous electrical nerve stimulation (TENS) in detrusor overactivity, stress incontinence and interstitial cystitis, an English-language literature search using Medline (1984-1995) was undertaken with detrusor instability, incontinence, interstitial cystitis, neuromodulation, transcutaneous electrical nerve stimulation and urodynamics as keywords and the material so identified was reviewed. The mode of action of TENS and optimal stimulation parameters in bladder dysfunction remain unclear. Lack of strict selection criteria and deficient reporting of subjective and objective outcomes precluded full assessment of therapeutic efficacy. A beneficial effect was evident in some studies of detrusor overactivity and interstitial cystitis. A trial of TENS in detrusor overactivity and interstitial cystitis refractory to conventional therapy would seem justified. Continued experimental research and further clinical studies will lead to refinement of the treatment modality.