Classification of cemento-osseous lesions of the jaws has long been a dilemma for pathologists. A group of 221 cemento-osseous lesions exhibited sufficiently distinctive clinicopathologic features to be separated into a specific category: focal cemento-osseous dysplasia. This entity presents as an asymptomatic, focal, mixed radiolucent/radiopaque lesion with ill-defined borders in the tooth-bearing areas. It was found to occur with greater frequency in women (88%) and in the posterior mandible (77%). The average age at presentation was 37 years and a relative predilection for black patients was observed. At surgery these lesions were noted to be hemorrhagic, gritty, and adherent to the surrounding bone. The gross appearance of multiple hemorrhagic fragments is of diagnostic significance. Histologic features include a cellular connective tissue stroma punctuated by irregular osseous and/or cementum-like calcifications. Focal cemento-osseous dysplasia is thought to be of periodontal ligament origin and to be non-neoplastic in nature. Further surgical intervention is not necessary, but periodic follow-up is recommended, because occasional cases were observed to progress into florid osseous dysplasia. Care must be taken to differentiate focal cemento-osseous dysplasia from central cementifying and/or ossifying fibromas, which are true neoplasms and require surgical treatment.