Gingival squamous cell carcinoma (SCC) has a relatively poor prognosis, because differential diagnoses ofperiodontitis and osteomyelitis are difficult to exclude. As such, gingival SCC is usually diagnosed late, following invasive procedures such as extraction or curettage. The purpose of this study was to classify gingival SCC patients into two groups according to the location of their primary lesion: dentate and edentulous, and to determine the appropriate treatment strategy by comparing clinical and histological features as well as treatment results. The medical records of 76 patients diagnosed with gingival SCC andtreated at one institute from 1 January 1993 to 31 December 2007 were reviewed. The overall 5-year survival rate was 60.7%, and the mean survival was 98 months. Factors affecting survival included bone invasion of the primary lesion (p = 0.035), neck node metastasis (p = 0.001), and local recurrence (p = 0.000). The results suggest that more aggressive treatment, such as setting a broad surgical field and enforcing preventive neck dissection, can improve outcome, although they are associated with increased rate of cancer bone invasion and neck metastasis in patients diagnosed with cancer after receiving invasive procedures.