Urodynamic evaluation of the incontinent female has come of age. It is no longer accept­ able to subject women to surgical procedures for urinary incontinence based solely on the physician's clinical impression of the cause of the urine loss. Multiple studies in the uro­ gynecological literature have told us that the error rate for stress incontinence is about 25% and the error rate for the unstable bladder is 50% when these diagnoses are based solely on historical data obtained from the patient. Unfortunately the patient is a poor witness to her bladder's activities and diagnoses arrived at without further evaluation are subject to error. Urodynamic testing allows the establishment of precise diagnoses using procedures that have been proven to be accurate. For the physician who has not had the opportunity to have fellowship training, the uro­ dynamic tracing is sometimes more of a mystery than a diagnostic aid. Physician training in the reading of urodynamic tracings is limited to piecing together information from the literature, textbooks and postgraduate courses. Unfortunately none of these sources can provide the experience necessary to become an expert in the interpretation of the physio­ logical and pathophysiological events depicted on the tracing. Artifacts occur commonly and may lead to misinterpretation of these events and even misdiagnosis if the reader of the tracing is not careful and fully informed on the nuances of the testing procedures. This is why this text was conceived as an atlas of urodynamic testing procedures.