Of crucial importance to any corporation is the relationship between management and its employees and their trade union representatives, and thus it is not surprising that the internationalization of management through the multinational corporation has had important consequences for industrial relations in general and trade union strategies in particular. This article identifies several dimensions of the internationalization of employment and then examines the concerns of host country and parent country union leaders with respect to multinational enterprises. A number of advantages accruing to the firms as a result of their multinational nature are discussed in the light of the single-state orientation of national unions. To counteract the strength of these enterprises, national, regional, and international union organizations have developed a number of new institutional structures and strategic thrusts. Union strengthening, legal regulation, and cross-national cooperative activities are explored as they occur at each level of the union movement, and it is suggested that international and regional industrial union organizations are stimulating international union collaboration with respect to specific multinational enterprises. However, the central role of the national unions combined with their single-nation orientation will in some cases retard the development of an international union bargaining capability.