Nine new cases of adamantinoma of long bone are presented. The age range, location, and symptomatology are similar to those in precious reports. Histologically most of the tumors have a "basaloid" or "spindled" pattern. A squamoid pattern with keratinization or an "angioblastic" pattern is seen less frequently. In all cases with adequate material there has been an associated frbrous dysplasia-like lesion is interpreted as being a part of the spectrum of mesenchymal differentiation of which the tumor is capable. Two cases in which metastasis occurred are compared to previously reported metastasizing cases. Few criteria are available that identify the potentially metastasizing tumor.