Despite the attention that offshore outsourcing currently demands in the public media, there is little empirical evidence on its economic impact. As a consequence of rising fears of job losses associated with the phenomenon, most existing research on the subject is primarily concerned with addressing related labour market issues. The impacts on productivity, however, have received only little attention. This paper surveys the empirical literature on offshore outsourcing and its productivity effects. Due to the small number of existing studies, the survey also includes research that may serve as indirect evidence of the phenomenon’s link to productivity, such as its effect on skill upgrading. The most apparent conclusion drawn from the review is that there appears to be no clear patterns as to how offshore outsourcing affects productivity, and that much depends on both sector and firm-specific characteristics. There are some indications, however, that positive productivity effects from foreign material sourcing depends on the degree to which firms are already globally engaged, but also that such engagements generally could be close to their optimum level in developed economies. There is little existing research on offshoring of services, but it appears that its productivity enhancing effects generally are small in manufacturing plants while being of a somewhat greater magnitude for firms in the services sector.