RT-qPCR, microarray platforms and miRNA sequencing are the most common techniques used to determine microRNA (miRNA) expressions. One of the most important issues in studies these techniques are used is the normalization of the data by using appropriate normalization method. The purpose of normalization is to eliminate the effects of biological and technical variations on study results. Numerous normalization approaches are used for normalization of data obtained from different techniques in miRNA expression studies. In this review, information about the most commonly used normalization approaches in miRNA expression studies is summarized.