MicroRNAs (miRNAs) are a class of small, noncoding RNAs that have been emerging as novel regulators in esophageal adenocarcinoma. Their role has been established in various aspects of esophageal adenocarcinoma including carcinogenesis, progression, treatment, and prognosis. Therefore, miRNA detection, profiling, and quantification have become extremely important for scientists and clinicians. As miRNAs are small, their detection can be challenging. There have been various methods developed to detect and/or quantify miRNAs. This chapter aims to introduce the fundamentals and methods of the most commonly used approaches including miRNA microarrays and quantitative real-time polymerase chain reaction (RT-qPCR) to detect and quantify miRNAs in esophageal adenocarcinoma.