Non-Hodgkin's lymphomas (NHL) are the third most common group of malignant lesions in the oral cavity and maxillofacial region. Most such lymphomas have been shown to be predominantly of B-lineage. The purpose of the present study is to analyze the clinical signs and symptoms and the clinical staging of B-cell NHL of this region. Eighteen adults, with B-cell NHL manifestations of the oral cavity and maxillofacial region, were available for this study. The clinical stage according to the Ann Arbor system was assessed by history, physical, and laboratory examination. Hematoxylin and eosin--stained slides and paraffin blocks were available for all cases. Histologic diagnosis was based on the WHO classification of tumors. The mean age of patients at the time of biopsy was 64 years. At the time of the disease presentation, according to the Ann Arbor system, 11 patients were in stage IE, 2 patients in stage IIE, 2 patients in stage IIIE, 1 patient in stage IVE, and 2 patients in stage IV. The typical clinical appearance was a painless local mass lateral or bilateral. Often there is a superficial ulceration of the tumor mass. Tonsillar NHL was the most frequent site occurring in 8 patients followed by NHL of the oral cavity, of the salivary glands, and of the mandible. Grading revealed that most cases were high grade (11 cases), followed by the cases of low grade (5 cases) and intermediate grade (2 cases). All the different histologic types may be observed, but the most frequently encountered is the diffuse large type. The B-cell NHL may involve both osseous and soft tissues of the oral cavity and maxillofacial region. The favored sites are tonsils, palatal mucosa and parotid glands. The typical clinical appearance is a painless local mass lateral or bilateral. Often there is a superficial ulceration of the tumor mass. According to the Ann Arbor system, the majority of the cases at the time of diagnosis are in stage I or II. Most patients have high grade disease. All the different histologic types may be observed, but the most frequently encountered is the diffuse large type.