STUDY OBJECTIVES: To build a simple in vitro uterine perfusion model for investigating the clinical effectiveness of endometrial ablation. DESIGN: Comparative laboratory and in vivo study (Canadian Task Force classification II-2). SETTING: University teaching hospital. PATIENTS: Women undergoing hysterectomy for menorrhagia with uteri of normal shape and size. INTERVENTIONS: A single 5-minute freeze, followed by an active thaw was applied to the endometrial cavity of uteri in vivo and in the in vitro perfusion model. MEASUREMENTS AND MAIN RESULTS: Endometrial/myometrial temperature change was measured continuously during the cryosurgical procedure. Depth of cell death was measured using nicotinamide adenine dinucleotide diaphorase enzyme assay. There was no significant difference in temperature change and depth of cell death in endometrial/myometrial tissue between in vivo and in vitro perfusion experiments. CONCLUSIONS: The in vitro perfusion model described is a useful tool for investigating endometrial cryoablation and has potential for investigating and developing other intrauterine surgical modalities.