The beginnings of oil exploration and production in our country reach as far back as 1883 when the first oil refinery in Rijeka was put in operation and 1932 when the oil production in Gojlo began. All this experience has been integrated into STSI.
In the process of restructuring of INA - Industrija nafte d.d. through the integration of all INA’s resources, in 1998 an independent organisational unit under the name STSI - INA Technical Services Sector was established.
In 2001 INA, founded a limited liability company STSI – Integrated Technical Services Ltd. with the head office in Zagreb, registered with the Commercial Court in Zagreb on 20 December 2001.