Uterine myoma is one of the most commonly encountered gynecologic problem in daily ultrasono-graphic practice, and is one of the few conditions with which specific histologic diagnosis is possible by ultrasonography in selected patients as well. We recently analysed ultrasonograms of 132 cases of uterine myoma and 31 cases that showed simllar ultrasonographic findings of myoma, histopathologically verified in both cases. The results were as follows. 1. The diagnostic accuracy by ultrasonography was 93%. 2. The most common ultrasonographic findings of uterine myoma were nodular enlargement of uterus and irregular internal echo texture changes. 3. It was not possible to differentiate the various kinds of secondary degeneration by ultrasonography, except for calcification and cystic change. 4. It was usually unable to differentiate solitary from multiple myoma, and subserosal, interstitial and submucosal types from each other by ultrasonographic findings alone, except for the usual cases of exophytically growing subserosal mass. 5. The most frequent disease that is hard to differentiate from small uterine myoma was adenomyosis, and therefore it is considered necessary to include the adenomyosis in differential in the diagnosis of myoma causing moderately enlarged uterus.