AbstractAimsTo collect bladder diary frequency and volume measurements from asymptomatic males and to use these data to develop clinical reference values.Materials and MethodsComputer processed three‐day bladder diaries were collected from 92 males (median age: 46.2 years; range: 20.6–84.6 years) defined as “asymptomatic” by questionnaire. Minimum (Vmin), maximum (Vmax), and average (Vavg) volume per void (Vol/Void), 24‐hr frequency (F24), and 24‐hr volume (V24) were studied. Relationships of Vol/Void and F24 to age and V24 and of V24 to age were investigated by regression analysis.ResultsVmax and Vavg increased as V24 increased and decreased with increasing age (P < 0.0005). We found no significant relationship between Vmin and age, but Vmin increased with increasing V24 (P < 0.0005). F24 increased with increasing V24 and increasing age (P < 0.0005). We found a concave downward, curvilinear relationship between age and V24, which, while it did not reach statistical significance, was very similar in shape to age versus V24 relationships found by other studies of larger datasets.ConclusionsOur results suggest that reference values of F24 and Vol/Void should be adjusted for their relationships to the patient's age and V24. Regression equations expressing these relationships can be used to make these adjustments. From frequency histograms of residuals the difference between the patient's actual and expected reference measurement can be ranked within the reference population as a percentile. We illustrate this method by using our results to calculate age‐ and V24‐adjusted 5% “normal limit” tables of F24, Vavg, and Vmax. Neurourol. Urodynam. 27:198–204, 2008. © 2007 Wiley‐Liss, Inc.