MicroRNAs (miRNAs) are single-stranded, small RNA molecules of 21–23 nucleotides that are primarily involved in the regulation of gene expression. A number of recent studies have shown that miRNAs play a vital role in signaling pathways important for human oncogenesis and may hold promise as potential biomarkers for cancer diagnosis, prognosis, and therapeutics. Microarray-based expression analysis is an emerging and powerful strategy for initially identifying candidate miRNAs, which can then be correlated to specific biological process such as carcinogenesis, and eventually developed as a molecular signature for a disease state. This chapter presents a protocol for miRNA microarray profiling using the Agilent platform, which is one of the most widely utilized technologies currently available.