Offshoring of services (OS), commonly defined as the international relocation of service activities that companies previously performed in their home country, has emerged as a relevant phenomenon in international business (IB). Over the past two decades, OS has grown rapidly in the global economy and it has increasingly attracted IB scholars' attention. In this study, we systematically review the literature to map and assess the body of IB research focused on the OS phenomenon. To achieve our goal, we identify and analyze a total of 79 studies that appeared from 1990 to 2014 in a select group of 14 journals that are widely considered leading publishers of IB research. This review seeks to make a threefold contribution to the IB discipline. First, it provides an in-depth analysis of the OS literature through a synthesis of the theoretical perspectives adopted and an assessment of the empirical findings obtained. Second, it offers an organizing framework that contributes to a more nuanced understanding of the OS phenomenon. Third, it identifies emerging topics on the OS frontier and suggests potential avenues for future research.