This paper aims at reconstructing the reasons why no close relationships exist between sociology and labour law. The problems outlined will be addressed both in theoretical and methodological terms. After dealing with the correspondence between specific areas of labour law and sociological issues and with the sociological tradition in this field, the author reconstructs the relationships starting from E. Durkheim's thought, devoted to promote solidarity and social integration. The genesis of the split between sociology and labour law has been traced back to M. Weber and his controversy with the Verein für Socialpolitik. While Verein's intention was to inspire social politics during the industrialization process, Weber's intention was that social sciences should not be based on ideological options nor sustain political solutions. In contemporary times the gap between labour law and sociology is due to the fact that the social- economic sphere has prevailed on the juridical-political one. The author draws the conclusion that a stronger relationship between sociology and labour law is needed.