Several different types of RNA molecules such as microRNAs (miRNAs) have been detected within extracellular vesicles in the circulation. The detection and potential utility of these as disease biomarkers requires the ability to detect their presence with adequate sensitivity and to quantitate their expression. The potential for circulating miRNA to serve as biomarkers can be evaluated through their detection in association with specific disease states. Multiplexed detection of several miRNA simultaneously can be useful for discovery studies. We describe the analysis of miRNA from biological fluids like plasma and serum using the Nanostring nCounter platform. Assays can be used to quantitate the expression of miRNA using direct detection based on hybridization to target specific color-coded probes followed by counting each color-coded barcode digitally.