The dominant agricultural activity in Portugal is the production of oil, with about 96% of the olives produced aimed at making this product. This study aimed to develop a technical commercial research project directed at marketing research in the oil sector in portugal, reviewing the production chain of olive oil in its complex: current size, development trends and research in the sector. A database was set up based on information from the mills of portugal. To build this database we conducted a survey on some sites in portugal related to the production of olive oil such as the website of ministry of agriculture, yellow pages of portugal, house of oil and through direct contact with some important associations and cooperatives oil production in that country. After creating the database a questionnaire was given to mills, asking for general information about the mill, on processing, product and machinery, business information and related marketing and services. Of the 97 mills surveyed, it was observed that most of them are considered as new mills (acquired in the last five years). An increased production capacity, and the replacement of traditional systems (using press and stone mills) for continuous systems (use of horizontal centrifugal twophase mills and metal) were observed. We conclude that portugal, in recent years, has undergone a change in the sector of olive oil and this can be seen through the modernization of the mills to increase production capacity, offsetting the increase in production and increasing consumption.