Olea europaea L. is an olive, a member of the Oleaceae family. Olive leaves contains oleuropein, a sekoiridoide which is responsible from many pharmacological activities including antioxidant, antimicrobial, antiinflammatory, antiatherogenic, anticarcinogenic and antiviral activities. For Turkey, as an olive producer country, olive is one of the economically and socially important product. Considering its potential in our country, oleuropein has a very important place and the scientific studies to be done with oleuropein. Taking into account the studies carried out, it is thought that oleuropein has important biological activities and it will shed light on the development of new drugs nowadays. Furthermore it is thought that developing more effective formulations and bringing in pharmaceutical technology and presenting them in standard pharmaceutical forms will contribute to the scientific world and the country's economy. In this review, various studies including the pharmacological activities of oleuropein in the olive folium included in the Oleaceae family have been reviewed. It is aimed to summarize the studies conducted with oleuropein and contribute to new studies.