Purpose: We tried to discover the voiding patterns, which was diurnal & nocturnal urinary volume and voiding frequencies in women with overactive bladder (OAB). Materials and Methods: All voided volumes, times and frequencies were recorded in 249 women with overactive bladder. The subjects age related changes in bladder capacity, urinary volume and frequency were evaluated. The causes of nocturnal urinary frequency and its increase with age in older women with OAB were evaluated using 3 days of voiding diaries. Nocturia was devided into three types: nocturnal polyuria, decreased nocturnal bladder capacity and mixed type.