Purpose: There is few available information about uroflowmetric parameters in women diagnosed with an overactive bladder. We carried out a descriptive study and analyzed uroflowmetric and cystometric patterns in these patients. Methods: Between January 2005 and June 2007 women 16 or older who attended Hospital Universitario San Ignacio for an urodynamic study with a diagnosis of overactive bladder were included in the study. Exclusion criteria were patients with known neurological disease or their secuelae, diabetes, urinary tract infections, or those receiving drugs that affect detrusor contractility like alpha blockers or anticolinergics. Results: 215 patients were included. 43 (20%) were healthy patients and 172 (80%) had an overactive bladder. Average age was 53.7 yrs in the study group (overactive bladder) and 50.8 in the control group. In the study group the average Qmax was 18.6seg vs. 19.9 in controls. Time to Qmax was 5.6 seg and 8.4 respectively (p=0,025). The acceleration flow rate was higher in overactive bladder patients, 4.3 vs. 3.8. This difference was not significant. (p=0.1641). No differences were found when comparing average flow (Qave) or post voiding residual volume. Conclusions: The acceleration flow rate is not a predictor of overactive bladder. Therefore cystometric measures continue to be necessary in order to diagnose overactive bladder syndrome.