A 48-hour frequency/volume chart was completed by 151 women without micturition complaints. The distribution of the parameters of the chart are presented. The chart was found to be a valuable and reliable instrument for assessment of micturition patterns. The mean voided volume, which takes into account both frequency of micturition and total voided volume, showed the best reproducibility of the parameters and is suggested as the parameter of primary importance. Attention should be paid to circumstances under which the chart is applied, as normal micturition behavior seems to be highly dependent on social factors.