Blue nevi are uncommon melanocytic proliferations. They occur mostly in the skin and occasionally in mucosae. Blue nevi of the sinonasal mucosa are extremely rare with only two cases reported to date. We report two more cases and review the literature. Compared with sinonasal malignant melanomas, which usually present as symptomatic tumors, sinonasal blue nevi are asymptomatic lesions found incidentally. A biopsy is required for a definitive diagnosis. Although none of the four cases had recurrence, given a rare but possible occurrence of malignant transformation in cutaneous blue nevi, complete excision with follow up should be the treatment of choice.