The prevalence of urinary incontinence increases with age, with a predominance of incontinence due to detrusor instability. The development of incontinence in an elderly person can be explained pathophysiologically by the development of age-related histological and functional alterations of the bladder, by increased nocturnal diuresis at the expense of diurnal diuresis and finally, in women, by a reduction of urethral pressure. The initial assessment is essentially clinical and must comprise evaluation of concomitant diseases and drugs likely to favour the development of incontinence, a voiding diary and assessment of the post-voiding residual volume. Only a test for urinary tract infection by dipsticks or urine culture constitutes an essential first-line complementary investigation, as urodynamic studies can be reserved for more complex situations.