Objective Report two positive sentinel node biopsies for sinonasal melanoma. Design Retrospective review. Setting Academic tertiary care center. Participants Patients who underwent sentinel node biopsy for sinonasal melanoma between November 1, 2014 and November 1, 2015. Main Outcome Measures Clinical course. Results Two patients were identified. Patient 1 (83M) presented with a sinonasal melanoma anterior to the left inferior turbinate and was clinically N0 neck. Lymphoscintigraphy revealed two sentinel nodes in the ipsilateral and three in the contralateral cervical basins. The left level I sentinel node was positive for melanoma and lymphadenectomy showed no additional metastases. Patient 2 (71F) presented after incomplete resection of a sinonasal melanoma of the left posterior maxillary sinus wall and was clinically N0 neck. Lymphoscintigraphy with single-photon emission computed tomography (SPECT/CT) localization revealed one sentinel node in the parapharyngeal space and another in the ipsilateral cervical basin. Metastatic melanoma was found in both nodes and completion lymphadenectomy was negative for additional disease. Both patients developed distant metastasis in less than 1 year after surgical resection but responded well to adjuvant immunomodulatory chemotherapeutic agents. Conclusion Sentinel node biopsy for sinonasal melanoma can provide crucial clinical evidence of regional metastasis prior to overt clinical signs and symptoms. This intraoperative tool has the potential to improve detection of regional metastasis and improve long-term outcomes of this aggressive malignancy.