Art.19 of the European Social Charter of 1961, ratified by Poland obliges Member States to guarantee migrant workers who are nationals of a party to ESC, protection and assistance. The author deals with obligation of equal treatment in areas of: remuneration, employment and other working conditions; trade union memberships and the enjoyment of benefits of collective bargaining, taxation and legal proceedings. He examines conclusions of the European Committee of Social Rights and states that Poland complied with obligations established in international labour standards towards migrants workers.