A 4-week randomised, double-blind, cross-over study is described which compared the effects of a combination of emepronium bromide and flavoxate hydrochloride with placebo on incontinence and cystometrogram findings in 20 female patients aged 59 to 88 years. All patients initially had detrusor instability demonstrated on cystometrography: 14 patients completed the study; on placebo 10 still had unstable bladders and on active drugs seven were unstable. The number of wettings over a 48-h period before the study commenced and at the end each course of tablets showed no significant differences; also the patients' opinions about the effect on their incontinence indicated that the majority had the same opinion of each course. Active drugs significantly increased residual urine but did not significantly alter the values obtained for maximum cystometric capacity or effective cystometric capacity (the latter volume being maximum cystometric capacity minus the residual urine). No correlation was found, on either course of treatment, between the change to detrusor stability and the amount of improvement in incontinence. Some side effects are described. Despite evidence of a pharmacological effect on the bladder and patients' opinions tending to favour the active combination, nonetheless the main results of this small study do not suggest that the combination of emepronium bromide and flavoxate hydrochloride is an effective treatment of urinary incontinence associated with detrusor instability in elderly women.