OBJECTIVES To describe our experiences with a continuous quality improvement process for the standardization of multicenter urodynamic studies (UDSs) in a multi-institutional network. Multicenter UDSs can have considerable variations in testing procedures, training, equipment, and reviewer biases. METHODS A quality control process was developed that included protocol development, certification of modynamic testers, central review to assess compliance with protocol and quality, protocol modifications, standardization of equipment and signal configuration, development of an electronic signal repository, and the development of UDS Interpretation Guidelines. RESULTS We describe our experience and process in the development and implementation of a standardized UDS protocol in a multicenter surgical trial for stress urinary incontinence. The process included our protocol development, quality control measures, standardization processes, electronic signal repository, and the need for UDS Interpretation Guidelines. A urodynamic testing procedures protocol was implemented successfully by 20 urodynamic testers at nine continence treatment centers. The protocol provides explicit and detailed guidelines for equipment, calibration, patient position, specific annotations, lay language bladder sensation parameters, visual leak point pressure techniques, modifications for prolapse, and data recording. A UDS Interpretation Guidelines document provides specific suggestions for validity and plausibility determination, expected ranges of urodynamic variables, and reasonable agreement of measuring systems. Both documents are available to urodynamic investigators on the Urinary Incontinence Treatment Network website (http://WWW.Llitn.net/resourcesforphysicians.htm). CONCLUSIONS Multicenter UDSs require a continuous quality improvement process and the development of UDS testing procedures and interpretation guidelines. (c) 2007 Elsevier Inc.