This study investigated the use of a one-week urinary diary in the evaluation of incontinent women. The sample consisted of 50 community-dwelling women, ages 55 years and older, ambulatory, and mentally intact, who were volunteers in a clinical trial on behavioral management for urinary incontinence. All subjects kept a urinary diary for two consecutive weeks. An analysis of the immediate (one-week) test-retest variability and correlations on weekly diurnal micturition frequency, nocturnal micturition frequency, and urinary incontinent episodes were performed in subjects with sphincteric incompetence alone (N= 34) and in those with detrusor instability with or without concomitant sphincteric incompetence (N= 16). In addition, information obtained on history was compared with that obtained from the diary. Diurnal micturition frequency, nocturnal micturition frequency, and number of incontinent episodes were highly reproducible and did not differ by urodynamic diagnosis. Test-retest correlations were highest with diurnal micturition frequency and incontinent episodes. Lower correlations were observed with nocturnal micturition frequency, with a significant difference observed between diagnostic groups. Although modest, significant relationships between data collected by history and diary were observed in the overall sample, but there were significant differences between diagnostic groups. The results indicate that a one-week diary is a reliable method for assessing the frequency of voluntary micturitions and involuntary episodes of urine loss.