BACKGROUND: Melanoma is one of the most aggressive and lethal skin cancers worldwide. To our knowledge, no specific or sensitive biomarkers have been clinically used to diagnose or predict melanoma prognosis. MicroRNAs (miRNAs) have been shown to regulate oncogenesis and tumor development in various cancers including melanoma. The aim of present study was to determine the clinical value of miR-424 in melanoma. METHODS: First, we examined the expression levels of miR-424 in tissue and serum samples of melanoma patients using real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Then, receiver operating characteristic curves were used to determine the diagnostic value of miR-424. Furthermore, the chi-square test was used to analyze the relationship between the expression of miR-424 and the clinical characteristics of the patients. Finally, the Kaplan-Meier survival analysis was applied to validate the prognostic value of miR-424 in melanoma. RESULTS: The results demonstrated that miR-424 expression was remarkably increased in tissues and serum of pa-tients with melanoma. Moreover, results of ROC analysis showed both tissue and serum expression of miR-424 can serve as diagnostic biomarker for melanoma. Meanwhile, miR-424 expression was significantly associated with tumor thickness (p = 0.031), metastasis (p = 0.010) and tumor stage (p = 0.005) and ulceration (p < 0.001). Finally, patients with higher miR-424 expression have shown decreased overall survival and disease-free survival than those with low miR-424 expression, implying that high miR-424 expression will contribute to poor prognosis of melanoma. CONCLUSIONS: MiR-424 may function as a diagnostic and prognostic biomarker for melanoma.