A survey of the clinical and cystometric characteristics of continent and incontinent elderly subjects living in a community has not been reported previously. Household respondents identified initially from a random probability sample were invited to undergo a free clinic evaluation followed by an invitation to free urodynamic testing. Of the 1,955 household respondents 456 women and 298 men attended the clinic. From this group 169 women and 94 men accepted the urodynamic invitation. Cystometric studies reveal a significant difference between the over-all prevalence of uninhibited detrusor contraction between genders, 7.9 per cent for women and 35 per cent for men. The occurrence of uninhibited detrusor contractions is more prevalent among incontinent than continent subjects and this difference is marginally significant. There is no significant association between uninhibited detrusor contractions and symptoms of difficult bladder emptying, irritative symptoms, voiding frequency, nocturia and urodynamic diagnosis of outlet obstruction (normal or high pressure and poor flow) but there were significant associations with responses to questions about the delay in getting to a toilet. The mean bladder capacities of men and women do not differ significantly between the different age groups but the capacity is significantly smaller for those with uninhibited detrusor contractions. The post-void residual urine volume shows no association with the continence status. These findings raise questions regarding our conventional thinking as to the etiology of uninhibited detrusor contractions, especially in men, and of urinary incontinence in general.