Odontogenic cutaneous fistula is pathological sinus tract originating from the oral cavity to skin of the face and neck. Geminated teeth are rare, morphological alteration of teeth.This paper reports a case of buccal skin fistula caused by the geminated tooth on theright side of mandible. The anatomical morphology of the geminated tooth and the periapical and periodontal bone destruction were comprehensively determined by doing careful examination and radiographic investigations including cone beam computed tomography (CBCT).In this case, crown of geminated microdontia present on mesiolingual side was extracted and performed the periodontal and root canal treatment of tooth followed by the restoration of the normal occlusal relationship. This case explores the use of appropriate diagnostics and therapeutic measures for the complex cases.