Carcinoma of the gingiva is a significant risk to patients because the asymptomatic characteristics of erythroplastic lesions are not always readily identified. This case report shows the similarity in clinical appearance of squamous cell carcinoma of the gingiva to the common inflammatory changes associated with periodontal disease. A similar clinical presentation might be seen in any lesion with increased vascularity, including Kaposi's sarcoma associated with human immunodeficiency virus infection. Any erythroplastic change involving the oral mucosa should be viewed with suspicion and, if not resolved after removal of local sources of irritation, must be biopsied to establish a definitive diagnosis.