The article deals with the evolution of labour law sources in Poland (legislation, collective agreements, internal acts issued unilaterally by the employer). Before 1989 the labour law sources were deeply influenced by the specific attributes of the political and economic system in which the dominant role was played by the state as the main owner and the subject organising any and all economic activity. The real social dialogue was non- existent. Nowadays the social dialogue constitutes one of the foundations of the socio-economic system of the Republic of Poland. As a result, working conditions may be determined autonomously by the social partners (the state guarantees the minimum employment standards). On the other hand, the text discusse...