Amele Birliği established according to the law numbered 151 that regulates the rights of workers in Zonguldak-Ereğli coal field in 1921, is the first modern social security institution of Turkey. Amele Birliği which can be seen a as a very advanced step compared to the period did not only deal with compensation of damages, aids to the workers in cash and kind but also handled with required measures about worker health and workplace safety and determining the minimum wages. However, the difficult conditions for benefiting from the institution's benefits has caused these benefits to be insufficient to reach the all workers in need. By also participating in trade union activities in the region during periods when union establishment is prohibited, Amele Birliği has filled an important gap. However, the organization has lost this quality and has become firstly an employer-driven and then state-driven institution. In parallel with the establishment and growth of social insurance system in 1945, Amele Birliği has lost its character as a primary social security institution and has become a complementary social security mechanism.