Objective: To estimate whether the use of a low-cost cystoscopy model effectively trains residents in cystourethroscopy and to validate the model as a teaching tool. Methods: A randomized, controlled, and evaluator-blinded study was performed. Twenty-nine obstetrician-gynecologist residents had access to fresh-frozen cadavers on which baseline cystoscopic skills were assessed using the validated Objective Structured Assessment of Technical Skills checklists for cystourethroscopy. Subsequently, residents were randomized to one of two arms, a didactic study arm using the cystoscopy model and a control arm. Repeated technical skills testing was performed. Results: The study group demonstrated statistically significant decreases in cystoscope assembly time (128.8 seconds at baseline to 54.9 seconds postintervention; P=.005), and increases in task-specific checklist scores (from 59.3 at baseline to 92.9 postintervention; P<.001) and in global rating scale scores (from 61.0 at baseline to 87.8 postintervention; P<.001). Further, there was a significant improvement in task-specific checklist (P<.001), global rating scale (P=.002), and knowledge quiz scores (P=.011) in the study arm compared with the control arm. Conclusion: Use of the bladder model exhibited validity in enhancing performance and knowledge of cystourethroscopy among ob-gyn residents. © 2010 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins.