Objectives <p>Mold therapy using gold-198 grains (Au-mold therapy) is a radical treatment for early stage oral cancer owing to its localized delivery of radiation. Understanding the efficacy and limitations of Au-mold therapy is crucial for optimizing treatment protocols and enhancing outcomes. Thus, this study evaluated the treatment outcomes of Au-mold therapy in patients with hard palate and gingival cancer and assessed its feasibility as a therapeutic modality.</p> Methods <p>This retrospective study analyzed data from 37 cases with hard palate and gingival cancer who received Au-mold therapy alone. Treatment outcomes and complications were evaluated, and the dose distribution of Au-mold therapy was simulated using clinically available calculation systems.</p> Results <p>A notable 5-year local control rate of approximately 80% was noted in primary cases, whereas recurrent cases exhibited lower local control rates. Severe oral mucositis was not observed, and late complications, such as osteoradionecrosis and oral ulceration, were infrequent following Au-mold therapy.</p> Conclusions <p>This study provides insights into the use of Au-mold therapy for oral cancer. Promising outcomes in primary cases suggest its potential as a treatment option. Future research should focus on innovative strategies to enhance the efficacy of Au-mold therapy in oral cancer management.</p>