This paper presents the results of the first large-scale data collection conducted in the framework of the OECD/UNESCO Institute for Statistics/Eurostat project on Careers of Doctorate Holders (CDH). Doctorate holders represent a crucial human resource for research and innovation. While they benefit from an employment premium, doctoral graduates encounter a number of difficulties on the labour market, notably in terms of working conditions. These difficulties are to some extent linked to the changes affecting the research systems, where employment conditions have become less attractive. Women, whose presence among doctoral graduates has grown over the years, are more affected by these challenges. The labour market of doctoral graduates is more internationalised than that of other tertiary-level graduates and the doctoral population is a highly internationally mobile one. In the European countries for which data are available, 15% to 30% of doctorate holders who are citizens of the reporting country have experienced mobility abroad during the past ten years. Migration and mobility patterns of doctoral graduates are similar to those of other tertiary level and other categories of the population with important flows towards the United States, principally from the Asian countries, and large intra-European flows, notably towards France, Germany and the United Kingdom. While a number of foreign graduates receive their doctorate in the host country, a large share (and the majority in the Western European countries for which data are available) have acquired their doctoral degree out of the host country and experienced mobility afterwards. Mobility of doctorate holders is driven by a variety of reasons that can be academic, job related as well as family and personal.