The paper aíms to revive the memory of the person and works of Hugo Sinzheimer on the fiftieth anniversary of his death. The first part considers the period of his dutch exile emphasizing how Sinzheimer, during that period, changed his point of view regar-ding some of the key positions professed in his works during the Weimar period. In particular he admitted to having overrated, on the basis of Rudolf Stummler's neokantian positions, the role that law plays in the evolution of society. The second part considers the fundamental methodological contribution that he gave to la-bour law, through the revisitation of a serious discussion that saw as opponents Sinzheimer and Walter Kaskel. We note as final point, how his sociological legal method was taken up, after world war II, by part of the european labour law scholars.