Non-coding RNA molecules such as microRNAs (miRNAs) may play an important role in human carcinogenesis. Their expression has been profiled in many human cancers but there are few published studies in head and neck cancer. In this study, the relative expression of 261 mature miRNA genes was determined in nine head and neck cancer cell lines using an oligonucleotide array platform. Thirty-three miRNAs in the array were found to be highly expressed and 22 showed low levels of expression in all cell lines. Notable was the high expression of miR-21 and miR-205. Expression of several miRNAs was validated using Northern blot analysis. Potential targets of validated miRNAs included tumor suppressor genes, kinesin family member 1 B isoform alpha (KIF1B), and hypermethylated in cancer 2 (HIC2), and pleomorphic adenoma gene 1 (PLAG1). This study provides the largest genomewide survey of mature miRNA transcripts in head and neck cancer cell lines. Crown copyright (c) 2007 Published by Elsevier Inc. All rights reserved.