Abnormal uterine bleeding is a common gynecologic disease during the late reproductive and perimenopausal periods. Objectives: To evaluate necrosis depth of three systems of ablation, to measure and to record uterine serosa and cervical channel temperature. Material and methods: A comparative study was done in the University Hospital Dr. José E. González in Monterrey, NL, between the months of February and May 1997. Three different ablation systems were compared: multielectrode balloon, hot water balloon, and circulating hot water balloon. Candidates were women between the ages of 18 and 45 years, scheduled for hysterectomy, and with normal uterine cavity and normal endometrial biopsy. Eighteen patients were included in the study. Each patient was randomly distributed to one study arm, five for each ablation system and three for control. The temperature in the uterine serosa and cervix was monitorized at 1 and 2 cm. The tissue and cervical damage was evaluated with nitroblue tetrazolium and H&E. Results: There were statistically significant differences in the cervix temperature at 1 and 2 cm with the highest temperatures for the circulating hot water balloon between 56.2 and 67.7°C at 1 cm and 46.9 and 52.6"C at 2 cm. Histopathological results with NBT showed tissue damage between 2.6 and 3.1 mm, which is considered safe and adequate for a good endometrial ablation. Measurable lesions were present in the cervical channel with the three systems, but their number as well as their depth were higher with the circulating hot water balloon. Conclusions: The study demonstrated that the histopathological damage in the endometrium was similar with the three systems. However, the temperature was higher with the circulating hot water balloon, as well as the number and depth of lesions in the cervix, as compared to the multielectrode balloon and the hot water balloon. [ABSTRACT FROM AUTHOR]