Companies are fundamental actors in the protection of human rights and in the prevention of occupational risks originated by increased migration, although they do not have the same obligations of States to promote and protect the rights of migrants. According to the United Nations Guiding Principles on Business and Human Rights (UNGPs), the corporate responsibility to respect human rights includes both the duty to abstain from violating these rights and the adoption of positive actions to promote them. The article aims to discuss how companies should act to promote and protect the rights of migrants. First, it analyses the business responsibility to respect human rights, under the guidance of the UNGPs. Second, it analyses how companies should act with due diligence to prevent possible exploitations of their own migrant workers. At last, a transversal and multilevel dialogue between States, civil society and business is proposed for a greater protection and promotion of migrants.