A case of aneurysmal bone cyst in the maxilla is reported which developed following the excision of a cementifying fibroma from the same site. Aneurysmal bone cyst has been seen previously in association with other osseous lesions in the jaws and in other bones. A review of the literature revealed 58 cases of aneurysmal bone cyst in the jaws, of which 13 were associated with other bone disease. One theory of pathogenesis of aneurysmal bone cyst is supported by the finding of such hybrid lesions.