Aim: To explore the microRNA (miRNA) expression in renal clear cell carcinoma (RCCC). Methods: We compared the miRNA expression profiles in 11 pairs of RCCC and adjacent nontumorous tissue (NT) from 11 RCCC patients, using a mammalian miRNA microarray containing whole human mature and precursor miRNA sequences. To verify microarray results, Northern blotting was carried out on 5 randomly selected miRNAs. Results: Totally 81 miRNAs were identified valid expression in RCCC samples, 48 of which specifically detected in RCCC samples, 17 of which detected downregulated in RCCC compared to NT sample, 2 upregulated and 14 without significant difference. MiRNAs in RCCC tissues exhibit an overall higher expression level than NT tissue. The chip results were confirmed by northern blot analysis. Conclusion: Our study may help to clarify the molecular mechanisms involved in the pathogenesis of RCCC, and miRNAs potentially serve as a novel diagnostic biomarker of RCCC. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.